Nat Segaren drove his truck across the stink and rubble of the city in search of a last chance, four injured people stretched out on dirty blankets in the back.
He found it at the waterfront, where a triage team from the USNS Comfort looked at his passengers and agreed to take three but declined a partially paralyzed man with a brain injury - he would require too much of the floating hospital's resources and still probably would not survive.
Segaren thanked them, helped transfer the patients, then climbed back into his truck to drive off with his fourth passenger, who now was all but officially a dead man.
"I know there's nothing anyone can do," said Segaren, who works for a pediatric HIV program in Haiti and has been caring for 18 critical earthquake victims at a community hospital southwest of the city. "But I thought I would take a chance. The last-ditch attempt is to bring them to the Comfort."
The largest and most capable hospital in Haiti today, the Comfort is reaching its breaking point in ways that Segaren's dying passenger underscores.
The ship's space and supplies are overtaxed, forcing the crew to contemplate declining new admissions. The injuries are so abundant and severe that an otherwise acceptable caseload is unmanageable, forcing providers to choose between declining care and forgoing rest and food.
And the emotional demands of caring for the earthquake victims are made worse by the realization that the ship might have to accept a reduced standard of care for Haitian patients, who don't have the luxuries of long-term rehabilitation or evacuation to the United States.
"Even if every day we could have a critical-care flight of 20 patients out of here, we wouldn't be able to keep up," said Capt. Andrew Johnson, the ship's director of medical operations.
That reality, Johnson said, is forcing the medical staff to consider declining care to some critically injured patients, if only to free up room and resources that could be used to save more people.
"We can't look at each individual patient and say we're going to do everything for them that is possible, like we do in the United States. We have to acknowledge that we don't have endless resources," Johnson said.
It is a discussion common to disaster medicine, and a dilemma well known to military physicians and nurses caring for Iraqi patients, who aren't eligible for evacuation to Germany and the United States.
As a component of the American military's medical system, the Comfort is designed to fit in the middle of five tiers of care - more advanced than a medic or field hospital but less comprehensive than a brick-and-mortar medical center or a full-scale teaching hospital.
In Haiti, however, the third tier is the limit. Local patients with complex injuries that require long rehabilitation and recovery, such as brain or spinal injuries or severe burns, have nowhere else to go.
As a result, the Comfort finds itself caring for many patients whose injuries, while not necessarily beyond the capabilities of the ship and crew, call for a vastly disproportionate amount of time and resources.
Already the ship is caring for more burn patients and premature infants, for instance, than it can handle. It has run out of breathing ventilators, and incubators for sick babies. The operating rooms are on a 24-hour schedule.
There's a paraplegic patient with no known relatives or family members to come get him. Another patient, with a blood clot in his lungs, will require a breathing machine for months, tying up a bed and a ventilator that might save 10 people over that time.
An aid organization dropped off a gangrenous patient, who requires an amputation to live but declined the procedure, and that patient is now all but certain to die a slow, resource-intensive death in one of the Comfort's increasingly scarce treatment beds.
The earthquake is largely responsible for the problem, but so is Haiti itself, which barely had a health system at all by American standards. Doctors in the Comfort's pediatrics ward estimate that 20 percent of their patients suffer from serious pre-earthquake medical conditions that are too far advanced to be treated on the ship or anywhere else. One patient, the sole surviving child of a mother of four, arrived at the ship with an enlarged heart and chest tumors. The condition was congenital. The child was not an earthquake victim, but still received a full measure of treatment and care from the ship's crew.
"Whether we like it or not, we're the end of the line," said Cmdr. Tim Donahue, director of surgery on the ship.
Capt. Jim Ware, commander of the ship's medical facility, said the Comfort has cared for more patients in the last five days than it did during all of the two wars in Iraq. With a patient population of more than 400 and a staff and crew of more than 1,000, it has been transformed, in less than a week, from a dormant hospital floating in Baltimore into one of the busiest U.S. Department of Defense medical facilities in the world.
The ship has a theoretical capacity of 1,000 patients, though half the facility's beds are designed for patients who require "minimal care."
And since arriving in Haiti, the Comfort's crew has identified a weakness that makes many of the remaining beds difficult to fill. In the ship's recovery wards, the beds are all stacked in pairs, like bunk beds. But many patients are too sick to climb into an upper bed.
A key to managing the patient load in Haiti, ship officials agree, is proper triage, assuring that the Comfort doesn't get flooded with patients too sick to treat or too well to benefit from its advanced care.
The difficulty of that prospect was apparent, however, at the ship's staging facility, where the Comfort's crew turned away Segaren's brain-injury patient Saturday. Several hours earlier they decided to take a chance on a 30-year-old woman with sepsis from an infected wound, but noticed she was dead as crew members brought her to a waiting helicopter.
To care for all the would-be patients in Haiti's mountains and valleys, to treat all of their severe injuries, with little help from a barely functioning local health care industry, Johnson said he suspects three USNS Comforts wouldn't be enough.
"It's so overwhelming. It's just impossible to get the level of infrastructure in place that we have in the United States," he said.
Physicians and nurses on the Comfort held a late-night meeting Saturday, called by Johnson, to begin a dialogue about the strains of their humanitarian mission. One doctor said he was so stressed and overworked he feared he was on the brink of making a serious medical mistake, and said others felt the same way.
The meeting was interrupted by a voice on the ship's intercom, calling the chaplain down two decks to the emergency room.
Then the group resumed a discussion about disaster medicine's unpalatable realities.
"We need to recalibrate what we consider good care," said Cmdr. Mark Marino, head of nursing. "It may just be a bed to sleep in, some pain medication and a little water."
"He might have died there, instead he's going to die here, but you know what? We're going to care for him," Donahue said of one patient.
The meeting ended when the intercom interrupted again, this time with the nightly prayer, first in Creole, then in English.