The heartbreaking death of a Canton dad on Sunday — leaving two small children orphaned just months after his wife succumbed to cancer — has mobilized the grandparents, aunts and uncles to care for the children, while friends and even strangers are raising tens of thousands of dollars for their support.

Stephen Furbush, 39, was found dead Sunday morning in the same bed where his wife, Kristen, died in November after a monthslong battle with brain cancer.

“The kids were almost getting back to some kind of normalcy,” said Kristen’s father, John O’Keefe. “And then bang, this happened. It’s crazy. I don’t know why.”

Patrick, 3, doesn’t fully grasp the loss, said Mark Furbush, 35, Stephen’s brother. The family struggled to break the news to Kayley, 6, on Sunday.

“She immediately grasped onto the nearest family member and started sobbing,” he said. “She just went through this two months ago with her mother, and we explained to her, ‘Kayley, you have two angels now looking down on you.’ ”

Mark Furbush said his brother spent Saturday night at home, watching the Patriots game with a few pals. One of the friends stayed overnight, he said, and woke Sunday to make the awful discovery. The cause of death has not been determined but authorities say it is not considered suspicious.

Mark Furbush said his brother was a “rock” for his children after their mother died, answering their questions and explaining the tragedy while grieving the loss of his Providence College sweetheart, whom he married in 2006. He had just put in his first full week back at Wellesley Bank, and bought an ?elliptical trainer and new clothes, all one size too small, in hopes of shedding some weight.

“He had a clean bill of health and he was on the right path. He was ?going to be taking care of those few extra pounds,” Mark Furbush said. “He was on the right path. Getting on as well as he could, as well as anyone could who had just watched his wife battle cancer unsuccessfully for last six months.”

Kayley and Patrick remain at their home in Canton, in the care of the O’Keefes — who at 64 and 62 are still working, though nearing ?retirement age.

“You’ve gotta do what you’ve gotta do,” said John O’Keefe, a plumber, who is getting help from the children’s aunts and uncles. “Between the bunch of us, we’ll get it done.”

The staggering loss sparked a surge of donations to the fundraising site Stephen Furbush had set up weeks for earlier for his kids. The total last night stood at $80,000, and fundraising events are in the works, including a basketball game at Kayley’s school and a benefit at Florian Hall in June.

“It’s kind of a testament to who they were, and the impact that they made in this world,” said Mark Furbush.

“It’s the sort of thing that, at a time like this … it makes it a little bit easier to know there’s people that do care about these two beautiful kids.”

To donate to the Furbush children, go to sharingcounts.com.