A 3-year-old boy was killed yesterday morning as fireswept through two floors of a District Heights garden apartment unit, Prince George's County fire officials said. Several apartments in the 16-unit building suffered smoke and water damage and all of the buildings's residents were left without power or heat as night approached.

Avon Little was found in the bedroom of his family's apartment, at 1928 Rochelle Avenue, authorities said, adding that the boy had apparently been trapped when the fire broke out.

Little was the second youth to die in a fire in the District Heights area this month. Shawn Warden, 4, died after a fire at his home on Drum Avenue last Dec. 12, fire officials said.

The fire began shortly after 11 a.m., officials said, in the second floor apartment of Walter and Sharon Butler, and spread to an apartment immediately above it. Firefighters were forced to break into two other apartments on the third floow with crowbars, and furniture inside one of the apartments was damaged.

Officials estimated total damage to the apartment unit at $20,000.

In the aftermath of the blaze yesterday afternoon, one resident, Michael Porter, stood guarding the broken door of his third floor apartment. He was wearing an overcoat. "I can't leave here because the door won't lock," hesaid. "And I can't sleep because it's too cold. I guess I don't have many alternatives."

Both Porter and his next-door neighbor, John Crossley, took time off from their night-shift jobs yesterday because they were afraid to leave their apartments unlocked.

Crossley said he was lying in bed yesterday morning when he heard the fire alarm. "I ran outside in my bathrobe, with no shoes," he said. "The hallway was filled with smoke, so I ran outside. It was cold, but there was no way I was going to go back after my shoes."

This isn't a good situation," said Crossley as he stood outside his apartment in his jacket. "But I guess I really have to give thanks. I'm lucky I didn't get trapped."

Residents of the apartment building were told yesterday that their doors could not be repaired until fire investigators had completed work. Late yesterday, those investigators were still at the unit, and had not yet determined the cause of the fire, officials said.