How did the Raleigh fire spread so quickly?

The structure wasn't complete, and the construction material appeared to be mostly wood. Coppage said that can be especially dangerous.

"It creates a challenge for us as firefighters," Coppage said. "It would add to the fire load in many aspects. Depending on if it's under construction and if it's covered with a sprinkler system. There's a lot of different elements that contribute to how intense the flame would be."

Raleigh Fire Chief John McGrath said while the use of wood to build facilities has become a controversial topic, the structure was being built to code.

"That building itself, while it was under construction, had been inspected 50 times. They met all code, safety and building code requirements," he said.

When firefighters run into a burning structure, the unknown can be unnerving.

"A lot of time with buildings under construction, you don't know what phase they are in," Coppage said. "A lot of it is unknown for us."

While McGrath said the building was to code, the fact that the building was wood made a significant difference in how fast the fire spread. Because sprinklers were not installed, it added a challenging element to the situation.