LAKEWOOD, Colo. (CBS4) – A teenager jumped into action as a fire burned a house next door. He rescued two people in Lakewood early Monday morning.

The fire started just after midnight on West Dartmouth Place. The two people nearly didn’t get out alive.

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Homeowners Liesel and Jim Woodman tried to get out but couldn’t quickly find the key to a deadbolt. It’s not clear if the deadbolt that stopped them was on the storm door or the front door, but by the time the door was opened a stranger helped save them.

The Woodmans are currently listed in critical condition at University of Colorado Hospital.

The back of the house burned the most, but it was a locked front door that trapped the husband and wife for a time as the house filled with smoke.

“I’m so sorry and my prayers are with you,” neighbor Donna Gerhardt said.

Gerhardt’s son Cody called 911.

“I saw flames just engulfing the back patio there,” Cody said.

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Cody found his neighbor Jim sprawled on the front lawn with another neighbor hovering over him.

“He was listening for breathing,” Cody said.

Cody believes the neighbor, identified by West Metro Fire as Michael Dillon, 18, might have risked his life saving the couple.

“His face was covered in soot,” Cody said. “I think he’s a hero. Nobody knows who could’ve dragged the man out of the house.”

According to West Metro Fire, their critical injuries could’ve been avoided if only the key to their front door’s deadbolt had been in the lock.

“If this is keyed, then obviously the key should stay in just like a knob, and then all you have to do is turn the key,” Gary Armstrong with West Metro Fire said.

Armstrong said leaving the key in the lock doesn’t encourage an intruder that much more.

“If people are willing to break glass, they’re probably going to be able to get into your house whether they can open the door or not,” he said.

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The cause of the fire remains under investigation. West Metro Fire needed 30 minutes to put out the stubborn blaze.