Its over as quickly as it begins. A thousand birds vaulting skyward in unison, a chorus of barking dogs. Instants later, a terrifying undulation of the ground, like standing on a broken potter's wheel spinning off its axis. Screams, breaking glass, crumbling stone. And then it's over. The earth stands still, but you still feel the wobble. 45 seconds that seem like hours. 45 seconds with the power to change everything.

And in El Salvador, it has. Twice, in fact, only a month apart. Just as a broken nation had begun to get on its feet, a second powerful earthquake again reduced entire small villages to rubble, and reawakened the horrible fear and uncertainty that had only begun to slumber.

January 13. Terremoto primero. Long rumored to be lurking in the future, the strongest quake in the nation's history brought the world's attention to El Salvador. In Santa Tecla, just outside the capital of San Salvador, a mountainside crashed on a suburban neighborhood, trapping hundreds. Similar scenes on a lesser scale were repeated throughout the country. Aftershocks finished off much of what the initial quake didn't. And displaced people by the thousands streamed into the main refugee camp at Cafetolon.

Just outside San Salvador, Cafetolon is the primary refugee camp set up by the government for the damnificados from the first quake. At its peak population, it contained perhaps 20,000 people, housed in neat rows of tents as far as the eye could see.

It was to work here that our group came to El Salvador. Small World Foundation is based in Miami, but it includes volunteers from across the United States and Central America. Founded as a reconstructive surgery organization (and this is still a major focus), Small World recently added a medical wing, which I direct, that primarily focuses on bringing basic medicine to rural communities throughout Central America. Lately, much of the work has been in Honduras and El Salvador.

On this trip we were a small group-Dr Larry Arnold (cofounder of the foundation), Lorena Garcia (who organizes our efforts in El Salvador), Glenda Johnson (who coordinates medical missions for several groups), our versatile assistant, Jody Bird, and me. For most of us, given our involvement in the country, this project was close to our hearts. For Lorena, it literally was close to home, hers being just minutes from the landslide in Santa Tecla.

The trip is supposed to be a reasonably simple mission of relief work in the camp at Cafetolon. And for a while, it is. The refugees have been in the camp for nearly a month, and most of their critical needs have been met. Epidemics of serious illnesses such as typhoid and cholera have been avoided. After ravaging El Salvador during the long wet summer, Dengue was thankfully absent for the most part, a result of the current dry season and a relative paucity of mosquitos.

Throughout the camp is an impressive array of international organizations. Feeding programs work around the clock cooking and serving meals to the long lines of people that never seem to end. Water trucks move up and down the rows of tents, filling the plastic jugs that each family lines up along the lanes. Workers on those same trucks aggressively mop up even the slightest spillage of water; they want the camp dry and mosquito-free, which it is. And people cluster around the medical tents, waiting for hours for a few minutes of time with a doctor.

Several physicians are in the camp when we arrive-a couple from Doctors Without Borders, a few residents from the national university, even two French nuns (physicians, too) dressed in full habit, despite the oppressive tropical heat. Most have been there since the first quake. They are tired, and happy to have some help.

We all work together, a good team. The problems are typical of a crowded refugee camp. Many cases of scabies and other skin infections, a lot of diarrhea, asthma exacerbated by the smoke from the thousands of fires that burn outside each tent. And, of course, the pervasive intestinal worms.

Some people come with chronic problems, the type we see throughout the developing world, even in times of relative normalcy. Congenital infections, orthopaedic deformities, blindness. As usual, these are difficult to assist beyond kind words and encouragement. One case that stands out is a 28-year-old woman left paralyzed on her left side as a result of polio acquired when she was 10. She was infected in 1983, during the long civil war, when epidemics of polio and other preventable diseases were common as a result of disruptions in the availability of vaccines to the rural conflict zones. Another casualty away from the battlefield-all too common here.

And so it is. Good work, but reasonably routine. Until February 13.

Sunny, warm, a clear blue sky. The morning seems typical. A little breakfast, an assembly of the group, and a short drive out to Escalon, where we have arranged a meeting with the Minister of Health to discuss our long-range goal of building a mobile hospital for use throughout Central America. We are hoping to get the minister's endorsement of the project, and then head out to Cafetolon for another day of work. Little else is on our minds as we walk through the parking lot of the hotel.

We are almost inside. Lorena is the first to notice. At first the quake feels like a strong wind, but then we notice we're shaking. It starts gently, but in a few seconds turns violent. The air is filled with the sound of screams and breaking glass, barely audible over the loud rumbling of the earth. All eyes turn to the hotel, fearing its collapse. We try to run, but even if our legs could work, we wouldn't be able to go anywhere because the parking lot is rolling with a series of fast waves.

As the tumult ends, we stand in dizzy disbelief. The feeling of intense fear is coupled with a thanksgiving to be alive. The hotel is still standing, and as we run for the car, almost all of us are thinking aloud, "How could this happen again, in the same place, to the same poor country struggling to recover from a month ago?"

It is a question that will be asked over and over in the days ahead, on the lips and in the minds of essentially everyone we encounter. And one for which there is no answer.

When we arrive at Cafetolon, the medical tents are abuzz with activity. A platoon of army soldiers is there with a transport, looking for medical volunteers to go with them into the epicenter of the quake. Rescue and relief.

Within minutes we are loaded and speeding down the highway out of San Salvador, our destination a string of mountain villages at the heart of the destruction zone. Even around San Salvador, the damage from this second quake is apparent. Homes and buildings collapsed that were standing the day before. Hillsides that have come crashing down. And everywhere, faces bearing the same looks of fear and trepidation.

Our first stop is Zacatecoluca, central city of the hard-hit department of La Paz. Testimony to the quake's fury is everywhere. Next to the police station, an old library is collapsed. Tiles from rooftops are scattered. Around what is usually a busy, noisy central plaza hangs an eerie quiet.

The hospital is teeming with the injured. Overflowing, patients lay moaning in the grass outside the hospital, the lucky ones with bandages and perhaps an IV. Others simply await their turn to be treated. Numerous open fractures, gaping lacerations, closed head injuries-severe, major trauma in an area unequipped to handle the occasional case, much less cases by the hundreds. How badly they could use a team of properly equipped orthopaedic surgeons.

Wounds are washed out, fractures splinted as quickly as possible. IM morphine for everyone, until the supply runs out. Cases needing an operation are taken to one of the ORs (two inside the hospital and two more set up in tents in the hospital yard). The dead are piled to one side, awaiting identification.

Every few minutes another truck comes in from the mountainside, loaded with injured people and occasionally a fatality or two. Choppers from San Salvador are supposed to be coming to evacuate the most serious cases, but they are yet to be seen. An angry frustration sets in.

But just as trucks come with more patients, individual physicians begin to arrive, eager to assist. Eventually, people power is in good supply. The limiting factor is a lack of supplies and capacity to handle the crush of injured people. Rapidly tiring, all push on, driven by desperation, limited time, and adrenaline.

Reports begin to come in about two small villages at the epicenter of the earthquake, San Pedro Nonhualco and Santa Maria Ostuma. The reports are of total devastation, and regular vehicles can't traverse the badly damaged roads. They don't have a suitable landing site for a chopper. No one has reached them yet.

Because we have a military transport, the physician in charge asks us to attempt to reach these villages and do what we can. If nothing else, they need identification of the dead, an accurate body count, and transport of the wounded back to the hospital in Zacatecoluca.

So we head up into the hills. The traffic on our side of the road is light, only us and a small truck carrying children's coffins. Down the other side come vehicles by the dozens, loaded with frightened people and whatever of their belongings they can carry.

We arrive first in San Pedro Nonhualco. It is a scene of surreal devastation. Everything in town is down-not a single structure survives intact. Some are half-standing, waiting for the slightest breeze to finish their collapse. Some are hollowed out with no roof. But most are mere piles of rubble. People sit in the streets or cluster under makeshift tents, plastic sheeting over sticks.

But they have been able to evacuate their most badly wounded, and the people there suggest we head on to Santa Maria, where they have not been so lucky.

Santa Maria straddles a ridgetop high in the mountains overlooking the sublimely lovely Lago de Ilopango, along the slope of a large volcano. Its simple houses and shops of adobe and tile line the single street that passes through. On another day it must have been a beautiful place.

But not today. The town is gone now. Not a single building undamaged, most of them destroyed. Behind the ruined homes under the same plastic sheets huddle the injured. A broken-legged dog drinks from a puddle of liquor spilling from a crushed store. As we approach he quickly hobbles off. On a pew of what had been the town church, its walls and roof collapsed around it, lays the body of a five-year-old boy. His mother and sister kneel by his side, crying softly.

As quickly as could be, those with serious injuries are loaded into the transport, and it speeds off down the mountain. We stay behind to tend to those less seriously injured.

At least less injured in the physical sense. We quickly set up and get to work. Everyone in town seems infused with a quiet panic. Almost all have a terrifying tale to tell. As we clean and bandage their wounds, we listen to their stories.

The town had been struck hard by the earthquake in January, which had its origins out under the Pacific, but the one today was felt to be much harder here at the epicenter. Structures that had been weakened in January came crashing down today.

One older woman has lost her niece this morning. "The first one didn't get her, but this one did." Several people had themselves been trapped, and sit stunned and silent amongst the rubble. A teenager visiting from San Salvador, all the skin scraped off his back, after narrowly escaping a falling roof beam, thanks God for his good fortune.

As we work hurriedly, racing the sinking sun, a powerful aftershock rips through the village. People stand still, faces ashen, too scared to run. More buildings are felled, the final blow for what had been left standing.

Word comes that a large house on the edge of town has collapsed, blocking the road out of town. Now in the near dark, we rush to the site and begin digging. For half an hour, the only sound is the scraping of bare hands along the ground and the clinking of broken tiles thrown to the side. We work in unison, strangers united by a common cause.

The road cleared, we return to San Salvador. All the way back the van is quiet, save the scratchy songs that occasionally make their way across the radio. I recognize in one of them the lonely chords of Carlos Santana's guitar. How appropriate. "Tears for Salvador."

The next day, after the rest of the group has returned to the States, Lorena and I load the car and again make our way out into the countryside. Local authorities in Cojutepeque have put out the word that physicians and medical help are desperately needed in this small city just east of San Salvador. We take our medical supplies, and all the blankets, rice, and beans that we can stuff into the car.

As we arrive in Cojute, we see evidence that the call has been heeded. A group from one of the medical schools in San Salvador is there, as is a team from the Ministry of Health and the Dominican Red Cross. We stop at a gas station to get some supplies.

As we're trying to figure out how to best direct our efforts, we have the good fortune to meet Edwin Navarette. Edwin was born in a small village near the San Vicente volcano, just down the road from Cojute and another region hit hard by the quake, but now lives prosperously in San Salvador and runs an electronics business.

He's on his way out to where he was born, to try and see what the people need and how he can help. From what he's heard, they've had no medical attention since the quake.

The road winds out of Cojute, and in a few minutes begins its winding course along the side of the volcano. The road is rough-broken dirt, now-and its dust fills the cab of Edwin's truck, swirling up into the light blue sky.

Several people are standing along the road, waving us down. We stop. It's the tiny village of San Juan Buenavista. Eleven extended familes live here. They've lost almost everything and have seen no one since the quake. From time to time, a chopper flies over, but their waving is to no avail. "No one knows we exist out here," the senior man in the village says.

They're anxious for anything we can give, and we set up a clinic alongside the road. The blazing sun of midday scorches the skin, but the villagers wait patiently, and express tremendous gratitude for even the simplest handful of aspirin. When we leave, an old woman who cannot speak mouths instead her words of thanks, as small tears run down her face and bead up in the dust.

Further down the road is the larger village of Nuevo Oriente. It's the same story. No one there since the disaster, save a couple of church groups handing out food. The water supply has been disrupted, and people carry with them their pails, buckets, and bottles of all sorts, waiting for the water truck to pass by.

Yet again, we set up a simple clinic in the yard of one of the families. Most houses destroyed, they, too, live beneath the multicolored plastic sheets that now paint the Salvadoran landscape by the thousands. Even if they could rebuild, why would they now? Who knows when the next tremor will come?

In many ways, that is the most pressing problem here, in this stricken village, like all the others. The uncertainty of it all. Tremors come without warning. The greatest earthquakes and the smallest rumbles all feel the same at the beginning. It's not "just an aftershock" until it's over.

We try to imagine what it's like to lie there in the dark, under a plastic tarp, having lost everything but your life itself, and fear the moving of the earth.

We've worked in areas such as this for years, and have seen thousands of children. But never before have we seen such looks of fear. Or been begged by children for something to help them sleep. Or seen a three-year-old screaming continuously, 48 hours awake. Or a boy who was trapped next to his sister beneath a fallen house. He was pulled out alive; she wasn't. He hasn't spoken since.

Even in Honduras, after Hurricane Mitch a few years ago, we didn't see this type of fear. There was shock and sorrow and grief. But people seemed to sense that it was over.

But not today, not in El Salvador. No one believed another killer quake would follow so closely on the heels of the first. So every little tremor stops the heart and lets loose the terror that people try to painstakingly put away every day.

After the last wound is tended in Nuevo Oriente and the sun again strains to shine as it slips behind the volcano, we prepare to leave. An old man, skin like leather, trudges out of the house where we had been working in the yard. He's carrying a worn cloth sack that he empties at our feet. Little green oranges spill out, 20 or 30 of them, and scatter along the ground. They want to give us something, a payment of sorts.

How fine-a delicacy, in fact. If they're lucky tonight, these people will have a little rice and beans and tortillas to eat. Much less, fresh fruit.

We each take one, the people smile, and we drive off down the road. Edwin has collected a list of what the people need, and will return in the following days to bring what he can. We hope to return with him.

How fortunate we are to have met Edwin, I say, and to have been brought to this place. What a coincidence, meeting him at the gas station like that. Lorena looks at me and smiles. Coincidences, she tells me, are the anonymous miracles of God.

I take my orange and bite into it. It's rock hard and bitter. I want to spit it out. But I don't. I eat the whole thing.

As we ride back to town, we quietly talk about what has happened. What will happen to these people, especially when the rains start, as they soon will? What about their villages? Will they rebuild? Can they? Or will they become yet another addition to the many who've become refugees from the only home they've ever known, having found this place unlivable for one reason or another.

It's hard to stop the tears. More tears for Salvador.

But at some point the tears have to stop. And stop they will, because there is work to be done here. This country has survived worse, and will survive this. Even if only for God's miracles, anonymous or otherwise.