When his health insurance refused to pay for the test and treatment that could save his life, it was fourth- and fifth-graders from St. Bernard’s elementary school who covered the costs of crucial medical care for little Stephen LaBruyere.

This is the story of caring schoolchildren from Old Mill Basin who generously gave so much of what little they had to help save the life of a 5-year-old boy stricken with leukemia.

It all began back in February, when Stephen began developing strange, bruised black and blue marks.

“I took him to the pediatrician, and he said it was probably a virus,” his mother, Dana LaBruyere, recalled.

They went to the hospital, expecting a quick diagnosis and the typical prescription of antibiotics. But when doctors told her Stephen had leukemia, she fell from her chair and crawled across the floor to telephone her husband.

“On February 4 at 10 p.m., my life changed and it will never again be as it was,” LaBruyere said.

Thanks to aggressive chemotherapy, Stephen has an 86% chance of survival — but before his treatments could begin, his health insurance balked at paying the bill.

Things looked bleak for the LaBruyere family, who moved from southern Brooklyn down to Boca Raton, Florida a few years ago.

After a highly successful Toys R Us raffle raised enough cash to cover his medical costs with money left over to spare, the St. Bernard’s kids followed through with daily prayers and inspirational artwork, along with gifts and books and the kind of genuine concern and compassion only children seem capable of.

The children sacrificed their snack money to finance what the health insurance refused to pay for. And they were thrilled to follow the story of Stephen’s recovery; delighted when his hair grew back after chemo, and anxious to finally meet him when he was well enough to take a trip back up to Brooklyn.

Last week, the children of St. Bernard’s celebrated Stephen’s ongoing recovery with a lavish pizza lunch.

“As a family, we came from Florida to New York to thank Mrs. (Roseanne) Kennedy and her fourth- and fifth-grade classes,” LaBruyere said. “These are perfect strangers who renewed our faith in humanity.”

Knowing the children were praying for him helped Stephen recover, his mom explained. And meeting his new friends at St. Bernard’s was also very important — “He was able to match a face to Nikki, who drew flowers for him, and Timmy, who drew the Sponge Bob that he loves.”

“We left with a suitcase full of toys, and our hearts full of love,” LaBruyere said. “Words can’t express how deeply we were touched.”