(INSIDE EDITION) - Matt Gannaway and his four children had decided to make a family project out of tearing down an old shed in his mother's Iowa backyard.
They were almost finished when things went terribly wrong - and the Gannaway children became first responders.
"We had it almost all of the way torn down. We were just waiting for it to fall the rest of the way," the father told InsideEdition.com Thursday. Just to be extra safe, he told his kids to back up and gave his cell phone to his eldest son, Ethan, who's 13.
"If anything bad happens, call 911," Gannaway told him.
The falling structure hit the ground and bounced, landing on the dad and pinning him. The blow knocked him unconscious.
Ethan called 911. And then Peyton, 11, Addison, 9, and Kaidan, 5, rushed to help their father.
"I think the adrenaline kicked in because the roof is several hundred pounds," Gannaway recounted. Two of the children were able to lift the heavy wooden structure while their siblings pulled Gannaway from the wreckage.
"I love them dearly, but they're the best helpers I could ever ask for. They're great children. They were all there to help. Even the 5-year-old was helping."
When he came to, the paramedics and firefighters were arriving, Gannaway said.
He remembers being in terrible pain.
He suffered a broken shoulder, scratches and a bloody gash to his head.
"I'm amazingly proud," he said of his kids. "They did everything, everything so perfect.
"It means the world to me that they would jump in and do whatever they could to save me."