The San Francisco Fire Department sent carbon dioxide specialists along with firefighters and paramedics to the blown electrical transformer on the Embarcadero near Pier 3 minutes after a 8:27 a.m. call, a dispatcher said.
No one was injured, but part of the road on the Embarcadero near Pier 3 was closed to traffic.
Transformers, which reduce high energy to lower levels, blow often, but this one is underground instead of on a power line or above ground, the dispatcher said.