Jim Ansara, a sturdy, 52-year-old former electrician from Boston, made his way to the devastated main hospital in the Haitian capital four days after the earthquake and went to work amid piles of lifeless bodies.

He found small generators and got them working. He spliced wires to light the makeshift operating rooms. He helped move patients around. For 12 days, working with Americans and Haitians, doctors and nurses, and hospital maintenance workers, he helped bring some order to the turmoil.

It’s a safe bet that none of the Haitians packed into the wrecked hospital complex had a clue that Ansara is a multimillionaire construction magnate who, with his wife, Karen, pledged $1 million from their personal fortune to help Haitians recover, and that while Jim was reviving generators in Port-au-Prince, Karen was back in Boston pumping donors to match their gift.

Ansara, who built one of the nation’s largest construction companies from scratch, and his wife, who spent years expanding the horizons of Boston fund-raising, have become powerful forces in Haiti’s recovery and rebuilding.

“Jim was saving lives on the ground and Karen was making sure we connected with the Haitian-American community here and getting the fund up and running,” said Kate Guedj, vice president for philanthropic services at the Boston Foundation who has worked with the Ansaras for a decade. “They are just incredibly genuine and incredibly engaged.”

In an interview shortly after arriving home, Ansara recalled arriving to the sight of more than 1,000 bodies clogging the hospital grounds. He said he couldn’t persuade some maintenance workers to go to the main generator at first because so many corpses lay in the path, awash in blood and body fluids.

Ansara did whatever was helpful. He helped set up a big cistern of drinking water for patients and staff, and took injured patients on a bed frame for treatment. It took another four days, but Ansara and other volunteers finally got the long-idled main generator repaired. They also wired in the temporary operating room, providing steady light to doctors and nurses who had operated with headlamps.

“If it weren’t for Jim’s involvement, we would not have accomplished what we did on the ground in the last two weeks,” said Dr. David Walton, a physician at Brigham and Women’s Hospital who arrived in Haiti just after the quake and worked side-by-side with Ansara. “He was so hands-on that he was taking things apart, and putting them back together.”

Meanwhile, from their home in Essex north of Boston, Karen went to work the day after the Jan. 12 quake, creating a Haiti relief and development fund through the Boston Foundation. The Ansaras put up $1 million to match public gifts to the new Haiti recovery fund, with the goal of collecting $2 million in all. But they didn’t want simply to buy food and blankets; they wanted to engage Haitian groups in the Boston area and let them take the lead on putting that money to the best use as Haiti rebuilds.

Philanthropy wasn’t a sudden impulse for the Ansaras. As intensely focused as Jim had been on making his Shawmut Design and Construction a leader in his industry, Karen spent years fostering a more activist, global-minded philanthropy in Boston. Last year, she helped form the New England International Donors network, pulling together like-minded givers and nonprofits. She is a voice on the website of Bolder Giving, which features The 50% League, that tiny fraction of Americans who donate at least half their wealth or income to help others.

The Ansaras’ Haiti fund has created a channel for small donations as well as individual donations of $50,000 and $100,000. The gifts have put the Ansaras more than halfway to their $2 million goal.

Ten years ago, the Ansaras created the Ansara Family Fund, helping Boston antipoverty projects at first. They had adopted three girls from Ecuador, giving them a glimpse of Third World poverty, and they began funding more international aid work as well. When they sold Shawmut to its employees in 2006, they committed far more of their money to the Ansara Family Fund - donating a total of about $16 million.

Ansara said he struggled to figure out what to do after his career at Shawmut.

“I’m a little different from other people who have sold businesses and made some money,” he said. “I don’t have any interest in managing money, I don’t love business, I’m not a serial entrepreneur. . . . I wanted to do something that had an impact in the world.”

Ansara traveled to Haiti last year at the request of a friend involved with Boston-based medical aid group Partners in Health to investigate a proposed job-creation project. That ultimately led him to work with Walton on building a 180-bed hospital at Mirebalais, a regional center an hour from Port-au-Prince.

Ansara plunged into the Mirebalais undertaking with Walton, and committed to spend a week a month in Haiti for the two years of the hospital’s construction.

Walton arrived in Haiti the day after the quake and helped treat 800 patients as part of a Partners in Health team. Meanwhile, Ansara had flown to Fort Lauderdale, Fla., where he helped organize emergency flights of doctors to Haiti. Walton said he called Ansara and said, “Please come, I need you.”

He and Walton slept a few hours a night at different homes for the first week, then stayed at the home of a godmother of a Partners in Health staffer. Ansara lost 15 pounds in those 12 days.

Ansara did not relax on his first morning home. He was scrambling to find someone to donate two oxygen concentrators so he could bring them to Haiti and install them at Partners clinics two weeks from now.

“We need to push ahead even faster and harder on Mirebalais. This is going to become a big, fast-track project,” Ansara said. “I’m going to need more help, more resources.”

For her part, Karen Keating Ansara spent last week talking with people at the Haitian Multi-Service Center, the Haitian Women’s Association in Boston, and similar groups to assess the needs through Haitian eyes. Both organizations are among the first recipients of small grants from the new Haiti recovery fund. Karen met Friday with Haitian clergy in Boston.

Walton, who is one of a half-dozen American staff in Haiti for Partners in Health, views both Ansaras as complementary companions in Haiti’s revival.

“There isn’t a moment since the quake happened that she has not been reaching out to individuals and organizations,” Walton said. “And with Jim, you’d never know who he is, or that he’s wealthy. He won’t tell you that. The only thing you see is an incredibly passionate, dedicated man, who helps out however he can.”

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