A 3-year-old boy died last night after falling from an eighth-floor window in a Northwest Washington apartment building as several horrified residents looked on.

The boy, whose name was not released last night, fell from what authorities believe was a bedroom window in his uncle's apartment in the Temple Courts building in the unit block of K Street NW. Authorities said a juvenile was in the bedroom with the boy, who fell shortly after 9 p.m.

The 3-year-old was taken to Children's Hospital, where he died at 9:37 p.m. from massive trauma, said hospital spokeswoman Barbara Cire.

Several residents said they saw the boy tumble out of the window, which authorities said did not have a screen.

"I was on the ninth floor, sitting next to the window talking to a friend, when I saw something falling," said resident Vernell Brown. "I said, 'Oh my God, that's a baby!' "

Another resident, who asked not to be identified, said she was standing outside when "I saw him coming down, and I heard people screaming, 'Oh no!' "

Residents said that a building security guard administered cardiopulmonary resuscitation to the child until ambulance workers arrived.

Authorities said they believe the child's uncle was in another room of the apartment when the incident occurred. Residents and authorities said the child's mother was in another apartment in the building and that his father was at work. Tenants said the couple moved into Temple Courts about six months ago.

Most of the windows in the 10-story brick building do not have screens, residents said. They said they have complained to management on numerous occasions, because many of the building's small children live on the upper floors.

"We complain to them every day," said Brown, who has lived in Temple Courts for 10 years. "The windows don't have screens or locks. Anybody can open them."