Fire swept through a house early Tuesday, killing four children and injuring three other people, one who jumped from a second-story window and two boys who were pulled to safety by a passer-by, a fire official said.

The passer-by, Nick Haviaras, saw the flames as he drove home about 3 a.m. At the house, he said, he heard cries: "'Help us, help us! We're in the basement!"'

Authorities said Haviaras, 43, broke open a glass block basement window, and pulled two boys to safety. The woman had jumped out.

The three who escaped were identified as Catherine Brownlee, 48, her 13-year-old son and a 14-year-old grandson, Fire Department spokesman Larry Gray said. She hurt her leg and ankle, and the two boys suffered burns on about 30 percent of their bodies, authorities said.

The victims were tentatively identified as Daina Howell, 14, and Brownlee's grandsons, Tylor, 8; Corey, 3; and Austin, 1, Gray said. It was unclear if Howell was related to the others.

The four children died from smoke inhalation, authorities said.

The fire was reported about 3 a.m. and appeared to have started in the basement, Assistant Fire Chief Brent Collins said. Authorities were trying to determine the cause of the fire, though they said arson was not suspected at this time.

The fire gutted the two-story home and scorched its white aluminum siding black. The house is in a neighborhood of mostly small bungalows.