A fire that officials say appears to have been deliberately set caused extensive damage yesterday afternoon to a new wing of Roosevelt Senior High School at 13th and Upshur streets NW.

It was the second fire of suspicious origin during the day at Roosevelt school and the latest in a series of apparent arsons plaguing schools throughout parts of Northwest Washington.

Roosevelt principal Carl J. Hines said the afternoon fire damaged an open-space learning center on the third floor of the school. "It was a new wing and new furniture," he said, adding that damage estimates had not been completed.

Hines said another fire earlier in the day was started in a trash container but was quickly extinguished.

At McFarland Junior High School next door to Roosevelt, six fires, all deliberately set, have been reported in recent days. School principal William Gray said the school cafeteria was heavily damaged by a fire on Feb. 3, and students have been eating lunch at Roosevelt since the fire.

An official at Cardozo High School said two fires have been reported in trash containers in that school this week.

School officials said they suspect the fires have been deliberately set by outsiders who are able to enter the school through unlocked doors. "We can't secure these buildings with all these [unlocked] doors, Gray said.

Fire regulations require that exit doors in schools remain unlocked.