Husband and wife tried not to let tension seep into their last days together. On Jan. 4, he would leave the family home in Queens for Haiti, where he was working to reduce deaths from natural disasters—not just the hurricanes that Haitians have come to expect but also a threat he believed was bigger, if less well known: earthquakes. She begged him not to go.

Rose Carline and Jean Arsene Constant were partners in every sense. They trained together as agronomists in the 1990s. They chose a common mission: saving Haiti from poverty and environmental degradation. Young and driven, they crisscrossed their native country, bridging the worlds of farmers and geophysicists and politicians; later, they had a son they adored. Their plans seemed to flow naturally, like water moving downhill, toward a shared life dedicated to Haiti.

But then their second son was born with a heart ailment. He needed sophisticated medical care. Suddenly, Rose Constant found herself living an immigrant’s life in New York. She gave up her profession, struggled with English, worked part time as a nurse’s aide. She found refuge in Queens, in the embrace of a Roman Catholic church, SS. Joachim and Anne, that is one of the city’s Haitian hubs.

Jean Constant kept working in Haiti—it paid well, and at least one of them was still serving the country. He visited Queens several times a year, but the separation hurt.

Now, on his latest visit, Jean Constant agreed to move to New York—but only after one last project. His ideas had finally been heard: Former President Bill Clinton, the United Nations special envoy to Haiti, was scheduled to visit the country and planned to warn that its next disaster might be worse than a hurricane. It was Jean Constant’s best chance to drive home the risk of earthquakes.

"Haiti needs me," he said.

The tug of war between country and family ran like a fault line through their marriage. On Jan. 12, it ruptured.

The earthquake killed Jean Constant and shattered his family, along with so much else in Haiti. In one sense, their loss is a speck among more than 200,000 dead. But it repeats itself, in kaleidoscopic variation, in countless families whose lives straddle the United States and Haiti.

"Back home," the price is measured in extinguished expertise; the quake took many of Haiti’s scarce technical elite, some of the people the country needs most to recover. In a house in Hollis, Queens, where the blinds stay closed all day, the cost is simpler to calculate: a broken partner and two shell-shocked little boys.

A CONNECTION

Since her son Chris could not survive in Haiti, Rose Constant, 37, followed her husband’s cousin, Ginette Bonhomme, to Queens. They went to Creole mass. They took turns picking up her son Michael, 7, from the parish school, where 80 percent of the students are Haitian. By this year, the phalanx of therapists visiting Chris, 5, seemed like family. But Rose Constant hardly felt herself without her husband and Haiti.

Jean Arsene Constant and Rose Carline Jean grew up in southern Haiti. Her mother was a tailor, her father a teacher. His family owned a cassava mill.

They met at the State University of Haiti. Philippe Mathieu, their mentor, remembers "watching love grow" between two intense, capable students. He was the witness at their 1998 wedding, and later, as agriculture minister, named Jean Constant his chief of staff.

Sometimes, the couple worked in rural villages, separated by twisting, bumpy roads. Sometimes he drove all day to surprise her.

Although they wrestled with Haiti’s ugly side—erosion and deforestation—they made others see its beauty, said Edith Bourget, a Canadian whose husband worked with Jean Constant to restore a collection of rare Haitian plants.

Their bond was palpable, she said; they seemed "fused together."

But as Rose Constant was finding her footing in New York, her husband found his dream job in Haiti.

The European Development Fund hired him to run a project to make Haiti less vulnerable to disasters. He told his wife, "I’m at the right place."

He and colleagues trained villagers to respond to emergencies. They warned about earthquakes amid scarce financing.

They pushed Haiti’s government and international donors to treat disasters as more than short-term emergencies. They wanted every aid project to factor in better land planning and construction to make disasters less deadly.

"There were just a few people driving that agenda in the country, and Jean Arsene was one of them," said John Harding, Clinton’s U.N. disaster risk adviser.

Jean Constant taught at three universities and helped pay several students’ tuition. Colleagues described him this way: "great synthesizer," "big heart, big convictions," reliable.

At cafes after work, they sang French and Haitian songs and talked shop. He spoke lovingly of his family.

He returned from his Queens "baby-sitting shifts," colleagues recalled, with joy "shining on his face."

To a few, he confided pangs of conscience over his wife’s burdens.

He called Queens daily. Cheery, impish Chris was thriving. He wanted to be president, "like Obama." Michael, a serious student, loved photography. Parish teachers remember Jean Constant’s last visit: his fatherly pride, his electric smile.

But his wife now questioned the mission she once shared. Before he left, she dreamed he was trapped inside a tornado, spinning helplessly, flying away.

She offered a deal: "You move here; I work two jobs; you study agronomy here." He said he would, after Clinton’s visit, planned for February.

"He believed Haiti will be another Haiti if we want," she said days after the quake. "He believed we will have a change."

A steely look crossed her face.

"He died for this mission," she said.

AFTER THE QUAKE

On Jan. 12, Jean Constant, 39, was at the European Union headquarters, meeting about disaster planning with other specialists. At 4:53 p.m., the building collapsed on them.

One version of events says they were still talking and most died. Another says that Jean Constant had stayed after the meeting, solving problems.

In Queens, Rose Constant watched CNN and cried.

The next day, Jean Constant’s grown son from a previous relationship, Jacquelaine, received a blank text message from him. False hope—a delayed signal or dying plea. His body was pulled out a day later, and his driver ferried the corpse to Camp-Perrin, Jean Constant’s hometown. He had waited days by the rubble to give his boss that rare gift, a proper burial.

In Queens, Jean Constant’s godmother, Jeanine Thomas, knelt at the church altar, her outstretched arms repeating the shape of the cross above. She wrote his name in the parish’s ledger of the missing.

The pastor, the Rev. Robert Robinson, told Rose Constant that her husband had died for Haiti. He meant it as a comfort; part of her took it that way. At school, teachers wrapped Michael in a blanket of affection.

But

At home in Queens, the family’s world had collapsed. Michael hung over the back of the sofa, peering between blinds at the rain. His mother’s face was puffy and blank.

Bonhomme, the cousin, told her that God would help navigate the calamity.

"God start it," she said. "He better finish it."

She concluded that God had sent Chris and his illness to save the family. Otherwise, they could all be dead in Haiti; Rose Constant might well have been at her husband’s meeting. Their marriage, anyway, was "too good to be true."

GRIEF AND ANGER

Rose Constant flew to Haiti to bury her husband. Thieves had scoured their broken house, taking clothes and shoes. She retrieved photographs in smashed frames and statements showing $9,000 in a bank that has never reopened. There was no death benefit, she learned, because her husband was a consultant, not an employee.

Back in Queens, life went on. Chris was eating so well that doctors would soon remove his feeding tube. Plus, he wanted to switch from piano lessons to drums.

Rose Constant had bigger problems: her $1,400 rent. A social worker said she could receive housing assistance only if she jettisoned her car, quit her Long Island job and moved into a homeless shelter. She was appalled.

Then there was the grief.

Michael told her, "Daddy died—I have to sleep with you every day." He wrote his father a letter.

A counselor suggested tying messages to a balloon and letting it go, but Rose Constant was not ready. The messages she had in mind were not friendly.

"I’m still mad," she said. "I have to pray about that."

April 20 brought respite: Chris’ birthday.

"We never thought he would be five," Rose Constant said, driving to a bakery to pick up a SpongeBob SquarePants cake.

In Haiti, Jean Constant’s boss is having trouble replacing him. The earthquake killed many qualified people and pushed others to emigrate.

Eric Calais, a geophysicist who worked with Jean Constant to install seismic warning instruments around Haiti but gave up when no foreign experts bid on the job, said bidders were now flocking "like wasps on honey."

Harding hopes the earthquake persuades people to see disaster planning as Jean Constant did, as "a moral responsibility."

In Queens, Rose Constant gropes for her old self, the one her children need. Chris vents his anger in school. His mother wonders how he will manage kindergarten if she cannot afford parish school tuition. On Michael’s birthday last month, she felt too low for a party. Instead, he took care of her. He bought her a Mother’s Day present—M&M’s—and made her a crown.

"My head is spinning," she said.

Like Haiti, she wants to rebuild but does not know where to start.