HOUSTON -

Families at a northwest Houston apartment complex spent most of the day salvaging what they could, after a massive fire destroyed their homes.

A frantic knock on the door in the middle of the night may have saved the lives of a mother and her four young children.

"Someone knocked and my mom got scared," said 11-year-old Steven Gomez. "She thought it was a burglar."

Instead, it was a neighbor trying to alert the young family that a two-alarm fire was raging outside their door.

"When we got out, we saw the flames," Gomez said. "We felt the heat. It was very dangerous."

Cy-Fair volunteer firefighters said they did everything they could early Sunday morning, but the flames and smoke were too massive. When it was over, a dozen Green Meadow Apartments were destroyed.

"I started having this attack of asthma and I couldn't breathe very well," the boy's mother, Elizabeth Chavez said. "The smell was really bad and it was so hot outside."

By morning, neighbors returned to the ruins and began salvaging what little they had left.

"That's not important," Chavez said. "It's important that (our family) is together. We're alive. We're healthy right now. It's a sad story but we're okay."

It's a story that could have ended tragically if it were not for that anonymous neighbor pounding on their door.

"Thank you for saving our lives," Gomez said about the person who alerted them of the fire. "He was very brave to do that."

The cause of the fire is still under investigation. No one was injured and the Red Cross is helping those who were displaced.

Arson investigators are trying to figure out what sparked the fire.