A boom followed by a flash and smoke from a Financial District manhole was not an explosion but a cable failure, according to Pacific Gas & Electric Co.
PG&E spokesman Joe Molica said officials are trying to determine the cause of the 6:30 a.m. incident at Battery and Pine streets. The failed cable will be sent to a forensics lab, he said.
Fire Department Battalion Chief Denise Newman said three passers-by reported what sounded like an explosion, followed by flames.
“Just a boom, a flash and then smoke,” she said. “Someone down the block said their lights flickered.”
Molica said there was no fire.
“Sometimes when a cable fails, it can produce a loud noise and smoke,” he said. No customers lost power during the incident.
Battery Street was briefly closed to traffic while PG&E crews worked to fix the problem.
“Luckily, nothing bad happened except a little traffic jam,” Newman said.