Flames engulfed a van as it drove down a street, killing three children and severely burning their mother.

The accident occurred about 8 p.m. Sunday in this Los Angeles suburb. While the mother was driving, she heard a popping noise coming from the dashboard area of her Ford Astrovan, said Los Angeles County Sheriff's Deputy Michael Irving.The van then caught fire and flames quickly spread, Irving said. It was not immediately known what caused the blaze.

"It could've been anything," Irving said. "The engine, whatever."