Richard Pollard, a 7-year-old Southeast Washington youngster, died early yesterday of injuries he suffered in a five-story fall after he toppled from an open, frameless window in an elevator shaft being built next to the apartment building where he lived.

Police said witnesses told them that Richard and his brother, Anthony Boots, 8, both of 601 Virginia Ave. SE, were playing in the unfinished shaft about 11 o'clock Sunday night, swinging on braces.

Richard plunged through the window opening when a brace came loose and he was unable to stop his swing. Anthony suffered cuts to his arms and stomach when he lunged toward his brother in a unsuccessful effort save him.

Richard died about two hours later while he was being treated at D.C. General Hospital.

Residents of the building at the Arthur Capper public housing project and officials of the housing agency were unable to explain details of the construction. But apparently access to the shaft was facilitated by the presence of temporary flooring placed at each level of the shaft while it was being built.

Richard's neighbors complained yesterday to a reporter of inadequate safety measures for the construction in their building, which houses many young children. Richard's mother, Saxaline Boots, said the contractors had removed all the locks to the elevator shaft several months ago when they completed the brick outer shell.

"The windows are so big a grownup could stand in one, and the children can just climb in there and do whatever they want," she said.

But public housing officials said that staff workers secure the open windows before they leave at the end of each working day.

"I don't know how this could happen, said Robert Lomax, head of the Department of Housing's management division. "Those windows are boarded up with plywood and two-by-fours are nailed around them. People are always pulling them off, but we replace them."

Saxaline Boots disagreed. "How can they call it secure when only two of the floors have boards on the windows?" she said. "The first, second and fifth floors have been open since we moved here in October."