A.J. Molaee was with his parents passing by the 8400 block of Orchard Road when he captured video of the aftermath of the blast. He says he saw a man lying on the ground.
On the property, two trailers filled with fireworks somehow caught fire as the homeowner and another man were inside. A nearby shed also caught fire.
Molaee and his parents stopped to render aid when all the chaos broke out.
Explosions could be heard in the background as A.J. yells, "get down" in the video.
Chopper 6 was over the scene around 3 p.m. as the mangled metal from the tractor-trailers were still smoking on the ground.
Video obtained by Action News shows fireworks going off as heavy smoke billowed into the sky from the blast.
With explosions still active, A.J., his dad, Tony, and another man ran up to pull the victim out of harm's way.
"I was afraid to even get too close because I mean the sparks and just more fireworks going off," said A.J.'s mom.
"He said, 'My friend Brian's in there in the trailer and my dog, is my dog OK? And I'm gonna die, I'm gonna die,'" recalled A.J. "We're asking him what happened? He said, 'I just walked in and the whole place exploded.'"
Nearby residents say they were terrified with what was going on.
"It shook the house, I mean the house just trembled, stuff came off my walls," said Deb Deily.
There was no immediate word on what caused the explosion. The ATF is assisting with the investigation.
On Wednesday, the victim was identified by officials as Brian Ehret, 50.