Explosion in San Francisco injures one, cause unknown

An explosion from an underground utility chamber in downtown San Francisco severely injured a woman and shattered a window at a Ralph Lauren clothing store shortly after 10:00 a.m. Pacific time Friday. According to a caller to KCBS radio, a woman was engulfed in flames after the explosion triggered a fire in the store. The fire was quickly put out.

A bomb squad is currently investigating the explosion, and the cause has yet to be determined. One official said the explosion may have been caused by an electrical transformer. A witness described a fireball coming out of the side of the building

Pacific Gas & Electric Co. company spokesman Paul Moreno has stated that "there was no indication of a gas leak." Moreno also described the aftermath of the blast. "The explosion did displace manhole covers — two round steel ones — and it also displaced a concrete cover as well," Moreno said.

Some accounts have described a rift in the sidewalk caused by the explosion below.

Construction worker Tom Demartini, who was sitting in his truck outside the Ralph Lauren store, stated he saw the sidewalk rise up six or seven inches. "It sounded like a big poof, then there was a lot of smoke," Demartini said. "One woman looked like she was badly burned."

The burned woman was taken to the emergency room at St. Francis Hospital. Hospital spokeswoman Linda Gillespie had no immediate comment on her condition. Her name was not released.

Workers in a nearby office building described how the blast shook their buildings and that they thought it was an earthquake. According to one woman, the elevator in her building stopped.

Scores of police have evacuated buildings several blocks around the explosion. Kearny street between Sutter and Market has been closed to both vehicles and pedestrians.