The small fire broke out around 11 p.m. Thursday in the basement of Fisher Plaza at an electrical vault — the section of the building where city power lines meet the building's transformers, said Seattle City Light spokesman Scott Thomsen.

Thomsen said that it appears equipment failure on the part of the customer caused the fire.

The fire forced the evacuation of the building and disrupted the late night newscast, said Rob Dunlop, vice president of operations for Fisher Communications Inc.

KOMO Radio and KOMO-TV are broadcasting Friday from remote locations.

Crews from several companies continue to work to get the building back on line, officials said.

Dunlop says he hopes stations can resume operations in the building later Friday. The stations affected, which remain on the air, include KOMO-TV and KUNS-TV and KOMO, KPLX and KVI radio.

Dunlop said he has no official word on what caused the fire.

The small fire also affected a data center in the building, disrupting service to multiple Web sites and other Web services. How many Web sites experienced problems because of the fire is not clear yet.

Verizon Communications Inc. spokesman Jon Davies said the company's DSL service in the Seattle area was temporarily disrupted.

Another company affected was Authorize.net Holdings Inc., based in Marlborough, Mass. The company provides credit card services for merchants.

Authorize.net's Web site was down Friday morning.