Three Northeast Washington men died in the city Tuesday night, apparently the victims of unrelated heroin overdoses, D.C. police reported.

One victim, identified as Raymond Samuel Washington, 28, was found about 7:40 p.m., unconscious and with a hypodermic needle sticking in his arm, in a lavatory of Lovejoy Elementary School at 12th and D streets NE, police said.

The ambulance crew summoned to the scene failed to revive him, and Washington, a construction worker who lived at 2119 I St. NE, was pronounced dead a short time later.

At about the same time, police said, a man identified as Carl Moore, 36, of 1133 Owen Pl. NE, was taken by two companions to the emergency room of Capitol Hill Hospital, where he died a short time later. Moore's companions told hospital employes that he had lapsed into unconsciousness after using narcotics, police said.

In a third incident late the same evening Joseph Rose, 37, of 4266 East Capitol St. was taken to D.C. General Hospital in a comatose state and with a hypodermic needle in his arm, police said. He was pronounced dead after efforts to revive him were unsuccessful.

The D.C. medical examiner's office said autopsies had failed to disclose the precise cause of death in any of the three cases and final determinations would probably be made in a few days when the results of toxicological tests are complete.