Charleston County coroner Rae Wooten says falling debris wasn't what killed them. "The cause of death is a combination of smoke inhalation and thermal injury," Wooten said.
The firefighters rushed into the burning furniture store Monday because they believed Jonathan Tyrrell, a store employee, was trapped inside.
"The first thing that popped into my head is I wouldn't be able to see my wife and little girl again," Tyrrell told CBS.
Tyrrell was in a small workroom when he heard the sirens. He knew that the only way out was through the warehouse, but when he opened the door, he saw stacks of furniture three stories high on fire.
He retreated to the workroom, headed for the air conditioning unit and tried to call 911. He said that while he'd never gotten a cell phone signal from that spot before, that time, the call went through.
"They told me to calm down, hug the floor and wait," Tyrrell said. "And as soon as he said, 'We're comin' to get ya,' the phone cut off."
Five minutes later, a firefighter's ax cut through the wall. Tyrrell was pulled out just before the roof collapsed. As he recovered by a fire truck, he realized one of the men who saved him was a few feet away.
"I leaned back and asked him, are you the firefighter who pulled me out?" said Tyrrell, overcome by emotion.
Two days after Tyrrell's ordeal, crews at his former workplace have begun removing debris so investigators can start looking for the fire's cause. They won't say how long it might take to find answers.