RICMOND, Calif. -- A young boy died and his mother was badly burned early Thursday as a two-alarm fire swept through their Richmond apartment.

Kristopher Love, a 5-year-old Richmond boy, was killed and three other people were injured when their apartment erupted into flames, officials said.

Firefighters were called to the apartment at 608 19th St. at about 12:35 a.m. The building is a two-story, four-unit complex and the fire was reported on the second floor, Richmond fire Chief Michael Banks said.

When firefighters arrived, they found the apartment engulfed in heavy smoke and flames.

The three adult residents of the apartment had already escaped the blaze and other residents living in the building were in the process of evacuating, Banks said.

Officials said the flames blocked the family's exit from the front door and anti-theft bars on the windows may have prevented Kristopher from fleeing the flames.

When firefighters went into the apartment, they found Kristopher lying on the living room floor. The boy was pronounced dead at the scene, Banks said.

"I tried getting into the window," said neighbor Guillermo Pescador. "But the smoke was just too thick."

Firefighters had the fire under control within about 20 minutes, but damages to the structure and contents are estimated to be about $300,000, Banks said.

Kristopher's 37-year-old mother suffered first- and second-degree burns to her arms, forehead and nose, and a 28-year-old woman who also lived at the apartment suffered second-degree burns to her left hand and an injured ankle, Banks said. Both women were taken to a local hospital for treatment.

A 17-year-old resident suffered wrist lacerations but was not transported to a hospital, Banks said.

Fire investigators remained at the apartment until about 3 a.m., but have yet to determine an official cause of the fire. Banks said the department's fire marshal would be following up with additional interviews today.