Underground vault explosion, fire startles San Francisco Pacific Heights neighborhood

An explosion and fire in an underground vault caused alarm in Pacific Heights Saturday evening.

San Francisco firefighters said the blast was first reported just after 8 p.m. on Pacific Avenue, near Laguna street.

Authorities at the scene said the explosion was caused by an underground PG&E vault.

No one was hurt but the fire damaged at least one car and the windows of several homes and businesses, officials said.

The ongoing investigation could affect traffic near the intersection through Sunday, according to authorities.