A 27-year-old Cheverly man was struck and killed by a Metro train in a subway tunnel on the Red Line between Woodley Park-Zoo and Dupont Circle stations during rush hour yesterday, authorities reported.

Police said David B. Taylor, a construction worker who lived at 6316 Kilmer St., was killed instantly when he was struck by a southbound train headed for Dupont Circle shortly after 5 p.m.

Taylor's body was found on a catwalk between the tracks, police and Metro officials said. It was not clear last night whether he had been standing on the tracks or leaning from the catwalk at the time of the accident, but Metro spokeswoman Beverly R. Silverberg said his presence in the tunnel was "clearly . . . unauthorized."

Silverberg said southbound passengers disembarked at Dupont Circle while a northbound train was delayed for about 5 to 10 minutes. Power was then shut off on the southbound tracks while trains continued to move northbound.

Trains headed north and south alternated on that track, with delays in service of about 10 to 20 minutes until power was restored and normal service was resumed shortly before 7:30 p.m.

Initial delays took place when power was accidentally cut off between Dupont Circle and Farragut North stations, Silverberg said. Authorities were unable to say last night why Taylor was in the tunnel.