The death of 8-year-old Martin Richard, and the serious injuries to his mother and sister, at the Boston Marathon bombing deeply touched Frank Fumich. The ultramarathon athlete from Arlington, and father of 3-year-old twins, decided the very next day to try to raise money for the Richard family by making a sacrifice of his own: to run three marathons in succession, each one 26.2 miles, to seek pledges for his run and to encourage others in the slightly unhinged world of long-distance running to do the same.

He was wildly successful. He completed the 78.6-mile run on Sunday morning in 19 hours, 38 minutes, and smashed his fund-raising goal of $26,200, or $1,000 for every mile of a single marathon. By Monday, more than $33,000 had been raised, and Fumich said, he intends to direct the money that surpassed the original goal to Jeff Bauman, the man whose gruesome leg injury was depicted in a photo seen around the world.

Sunday evening on Facebook, Fumich wrote: “I have just risen from a coma and I see $30,000!! OMG! Did all this really happen or was it just one crazy a– dream?! wait, I see my ankles look like my grandma’s, so it must be real!!! WOW! Speechless!”

Fumich, 45, is an experienced distance runner who was profiled by The Post’s Lenny Bernstein in 2011 because he has competed in completely insane events such as triple Ironmans, the Ultramarathon in Death Valley, Calif. , and something called the two-day Spartan Death Race. And yet, he told me Monday, “No matter how many times you run long distances, it’s no fun. It’s never easy. Especially when it’s on pavement.”

But nowadays, “everybody runs a marathon,” he said. So, with three people killed in Boston, “I just thought, how about if I just run three marathons?” He knew not too many people would join him for 78 miles, but he measured out a course along the Mount Vernon Trail from Gravelly Point at National Airport south for more than three miles into Alexandria. One lap went about 6.55 miles, and Fumich asked people to join him for one of those. Others were asked to do their own running, or simply their own pledging. A friend in Florida, Matt Nelson, set him up with a Web site through FirstGiving, where people could make pledges and describe their own runs. That site is here.

Nelson, a former Marine Corps major, said he and three others were running through trails in the Everglades in south Florida Monday night. He was joined by an Australian, a Cuban and a Bostonian. He said he tracked down the administrator for the Richard Family Fund, and that the family gave the event their blessing. “This could have been my family,” the father of three said in an e-mail.

Various people joined Fumich in Northern Virginia for one lap, one person ran a full marathon with him (Eric Rohnacher), another man (Todd Jubeck) ran two marathons, and his friend Bryan Selm ran all three marathons, all 78.6 miles, with him.

And when Fumich had recovered from the run, “we had exceeded our goal, which I never dreamed of.” The lifelong Arlington resident and Bishop O’Connell High School grad said he’s run about 50 marathons, and was gradually working his way through a list of doing one in all 50 states. He had planned to run the granddaddy, Boston, last. But now, “I think I’m going to run that next year. If I can qualify.”

If you want to donate to Fumich’s fund-raiser, go here.