A smoky three-alarm fire yesterday afternoon at the historic Washington Navy Yard disrupted evening rush-hour traffic on M Street SE and caused considerable damage to the contents of a building where uniforms for Navy personnel throughout the Washington area are sold.

In addition to Navy firefighters, about three dozen fire trucks and 175 firefighters from the D.C. fire department were sent to the scene of the blaze, in the 20,000-square-foot Navy Exchange building, just inside the Navy Yard near Ninth and M streets SE.

The building is closed on Mondays and was unoccupied at the time the fire was spotted just after 4 p.m., according to Lt. Cdr. Bill McLoughlin, a Washington Naval District spokesman. The cause of the fire was not immediately known and was being investigated late yesterday.

The blaze, which sent clouds of dark smoke billowing over the Navy Yard grounds, began above the ceiling in the 1 1/2-story brick building and spread from there, authorities said.

Although the Navy spokesman said a sprinkler system operated, firefighting activities were hampered by yesterday's 96-degree heat.

One Navy firefighter suffered a cut hand in combating the blaze, and one Navy firefighter and one District firefighter were treated for smoke inhalation.

After firefighters based at the 184-year-old Navy Yard called for assistance from the District at 4:26 p.m., the first D.C. firefighters to reach the scene quickly sent in a second alarm. The total response by the Navy and D.C. firefighters was equivalent to that for a three-alarm fire, said D.C. fire department spokesman Michael Tippett.

As fire trucks converged on the area, near the Anacostia River and the Southeast Freeway, about one mile south and east of the Capitol, traffic in the busy eastbound lanes of M Street was restricted to two lanes, from the normal four, authorities said.

Most of the damage caused by the fire was attributed to smoke and water, and no dollar estimate was immediately available. However, Tippett described damage to the merchandise as considerable.

According to McLoughlin, the exchange is a retail store dealing primarily in uniforms and patronized by personnel from throughout the area.