CENTENNIAL, Colo. - Investigators are combing through the charred ruins of a condominium at the Appletree Complex at East Peakview and South Dayton Street in Centennial, trying to determine what caused a two-alarm fire Tuesday morning.
Residents told 7NEWS they heard two or three loud explosions.
"I knew immediately that something was wrong," said Erik Lopez. "Then we heard banging on the doors and neighbors yelling, 'Fire!'"
Lopez's older brother, Marvin, said, "I walked out of the building and this wave of heat just hit me."
He said once he looked around the corner he saw flames shooting past the roof.
Erik Lopez shot cell phone video of the blaze roiling up the south wall of Building B. It shows part of the third floor balcony collapsing to the ground.
The blaze heavily damaged two units and caused smoke and water damage to four others.
Emergency personnel evacuated residents from the burning building and two adjacent buildings.
Becky O'Guin of South Metro Fire Rescue told 7NEWS that fire crews were able to knock the blaze down in a matter of minutes.
She said there were no injuries "but we did evaluate one resident for smoke inhalation."
That resident was the tenant in the unit where the fire started.
Tammie Nevid owns the unit. She told 7NEWS that her tenant got out safely, knocked on doors to notify neighbors, and then went back into his unit to retrieve some belongings.
"That’s when he suffered the smoke inhalation," she said. "But he is OK."
O'Guin said the fire started around 4 a.m. and was quickly brought under control.
She said investigators don't know if the blaze began on a balcony or inside the unit.
Nevid said her tenant doesn’t know either.
Residents who live in the adjacent buildings have been allowed back in their homes. Fire crews are still searching through the burned units trying to find the ignition source.
Marvin Lopez said he's grateful no one was injured.
"It's scary," he said. "It makes you realize that this could happen to anyone at anytime."
Lopez, whose family escaped the blaze in their night clothes, thanked firefighters for their quick response and their thoughtfulness.
"They were amazing," he said. "They ran in and grabbed my pants, my wallet and my keys. I'm really glad they did that."