A 17-year-old construction worker died and a co-worker was critically injured yesterday after they fell 60 feet off a building under renovation in Northwest Washington, authorities said.

Investigators said that one worker grabbed the other as he fell. Both then tumbled to an alley. Rescue workers found them lying next to each other.

Elkin Galdames of Baltimore suffered massive injuries and died at the scene. Officials said that his co-worker, Freddy Madrid of Baltimore, was taken to Washington Hospital Center. Madrid's age was not released. Both men were from Honduras, a co-worker said.

Fire and police officials said the accident occurred after Galdames and Madrid put a plank of scaffolding into place about 11:30 a.m. atop the Dunbar Theatre in the 600 block of T Street NW, in the area once known as Black Broadway.

When they stepped on the board, it gave out, officials said. As Galdames fell, Madrid grabbed him, fire officials said, and probably survived because he landed on the 17-year-old.

Police officials said the men were wearing safety harnesses. They said they were investigating whether the harnesses were attached to the building or scaffolding.

At least one other construction worker told police that the safety harnesses had been attached to the scaffolding, D.C. police Lt. Robert Neal said.

An investigator with the Occupational Safety and Health Administration was at the scene yesterday afternoon but would not comment.

"Clearly, safety equipment was available," said Alan Etter, spokesman for the D.C. Fire and Emergency Medical Services Department. "Whether it was being used or not is what OSHA and police will try to figure out."

Michael Kenneler of Brand Scaffold, which made the equipment involved in yesterday's accident, said he did not know why the plank gave out.

Police cordoned off the area with yellow police tape, and investigators were interviewing witnesses yesterday afternoon as a dozen bystanders watched.

The accident occurred about 11:30 a.m. at the Dunbar Theatre on T Street NW. The theater is in the area once known as Black Broadway.