Just before dawn, the bodies began arriving -- wrapped in sheets of plastic -- and pulled off pickups and makeshift stretchers at a morgue that was already overflowing before disaster struck Tuesday evening.
Within hours, the corpses were strewn across the gray brick courtyard outside the drab one-story building that houses the city's dead.
Amid the muffled cries of survivors searching for parents and children, workers began the grim task of burying those who perished in Tuesday's devastating earthquake that ripped through the impoverished capital.
For a country that has never been able to provide proper burials for its destitute, burying the estimated 45,000 to 50,000 may be Haiti's greatest challenge.
"You can't dig 50,000 graves,'' said Thomas Ewald, head of an elite rescue unit that arrived in Haiti Thursday morning.
Reminders of the disaster are everywhere: A man strapped to a hospital bed, his IV slung over a steel door. Children climbing through rubble in search of their parents. A woman screaming upon the discovery of her dead relative sprawled outside the Canape-Verte Hospital.
With few cemeteries and much of the country vulnerable to flooding, the Haitian government has already begun searching for burial sites outside the capital.
For now, the crucial mission of rescue teams is finding those who remain alive in the structures shattered by the 7.0 magnitude earthquake.
But by this weekend, several organizations under the umbrella of the United Nations will embark on a massive forensic investigation that could months.
"We're not talking thousands, we're talking tens of thousands,'' said Dr. Ciro Ugarte, regional advisor for the Pan American Health Organization, one of the agencies tasked with identifying the dead.
In Petionville, de facto morgues took shape on the cracked sidewalks where dozens of bodies rested. Many of the corpses had been covered with sheets, strapped to doors used as stretchers. One sheet bore a man's name: Joseph.
Passersby seemed to take little notice.
"What are we supposed to do?'' Renald Jean-Augustus, 34, a mechanic, said as he walked by. "Haiti is wrecked.''
For forensic workers now jetting to the capital, it's a race against time: Already, bodies are decomposing in the heat and humidity.
But getting to them will be a formidable task, with miles of the city's roads already crumbled and covered by debris. "There are no passable roads,'' said Tom Griffin, a lead investigator for the National Lawyers Guild who wrote about morgue conditions in Haiti. "In the meantime, you've got rotting bodies.''
Another unfolding crisis: the risk of water contamination from decomposing corpses increases each day. The last thing Haiti needs, said Griffin, is "overwhelming disease and infection.''
In most cases, teams are trained to carry out a series of crucial tasks to help identify victims and safely return their remains to family members. But in Haiti, much of their training will be cast aside for more rudimentary methods.
DNA sampling and medical records can't be used in Haiti, where many people are destitute and have never received adequate medical care.
More likely, recovery teams will fall back on the lessons learned from the powerful tsunami that swept through South Asia in 2004, killing more than 230,000: taking snapshots of the dead before the bodies decay and snipping pieces of clothing to show relatives.
After the tsunami, the dead were buried in mass graves. After Hurricane Mitch swept through Honduras in 1998, the government burned the corpses in vast fields.
In Haiti, Ewald said that thousands more will likely be buried en masse.
"You get to the point where because of logistics, you end up digging 200 very large graves,'' he said.
Another reason, experts say, is that there isn't any place in Port-au-Prince to dispose of the corpses. The few cemeteries that exist have been full for years.
"You have to leave the city to find a place to dig a hole,'' Griffin said. "Even if you collect them, where are you going to bury them?''
In fact, the government of Haiti has already started the process, burying 7,000 cadavers into graves 20 miles outside the capital. But thousands more are left covered in the rubble.
"We cannot afford to wait on the international community, we can't wait for them to do things for us,'' said Dr. Ariel Henry, the chief of cabinet for the Ministry of Health.
As international forensic teams begin to arrive, the survivors -- reeling from the loss of their homes and family -- are left wandering among the twisted corpses.
Bodies stretched for half a block along the street outside the Port-au-Prince morgue Thursday, where police, civilians and private companies dumped cadavers because there was no other place to take them.
An exasperated hospital manager said he was waiting for approval from the government to remove the bodies. When room ran out at the morgue, corpses were tossed onto the street, where a group of solemn onlookers stood staring.
Amid buzzing flies, toddlers were piled on top of naked adults -- their swollen bodies exposed to hundreds of people passing by. One dead woman was identified by a red ribbon and hand-written note tied to her left big toe.
Though the goal of forensic teams is to identify every dead person for their loved ones, the reality is that thousands will be dumped in graves -- their names unknown.
Lionel Gaedi stood dazed on Thursday, staring at the mass of bodies sprawled under the blazing sun.
"I have a brother and I don't see him,'' he said.
"It's a catastrophe. God gives, God takes.'' Miami Herald staff writer Jacqueline Charles contributed to this report.