Raleigh, N.C. — The quick thinking of a 12-year-old Raleigh girl and her 15-year-old brother helped save residents after fire broke out in an apartment building Monday morning.

Angel Watson was standing at a bus stop across the street from her home, at 4608 Brockton Drive, shortly before 7 a.m. when, she said, she saw smoke coming from the top of the roof of the four-unit apartment building. 

The fire was spreading fast, and Angel knew her mother and aunt were inside the apartment. She and her brother went running to bang on the door.

"I said, 'Oh my God, we've got to get out of here fast,'" Angel said. 

When she got closer, Angel said she saw flames shooting up the side of the building – just a few feet from where her mother lay sleeping inside.

"They wouldn't have woke up, because they didn't smell it," she said. "They didn't smell it until they got outside."

As the fire spread to three neighboring units, Angel and her brother pounded on neighbors' doors to warn them.

Antonio Navarro, who also lives in the apartment building, said he was going to go back to sleep when he heard the banging. He thanked Angel for her bravery.

Eight people in the apartment building were displaced by the fire. The American Red Cross is helping them find places to stay.

No one was hurt in the blaze, which began outside, behind apartment B, and spread to the attic of apartment C, according to a Raleigh division fire chief. 

The fire remains under investigation. A fire incident media report released Monday afternoon listed the cause of the fire as arson, but further details were not immediately available.