The explosion took place around 7:30 a.m. in the basement at 1010 Second Avenue, Sgt. Art Campa said.
The victims were doing some kind of work in the basement, but it wasn't immediately known if it involved the transformer, Campa said.
The three were taken to UCSD Medical Center, he said.
Multiple small brush fires near Otay Mesa and San Ysidro on Sunday forced authorities to shut down lanes and connector ramps of two freeways before firefighters could get the situation under control.
Sunday was Earth Day and hundreds of San Diegans took part in celebrating at one of the biggest events in Balboa Park. News 8 photojournalist Tim Blodgett shows us the 29th Annual Earth Fair.
An 18-year-old man was stabbed after he got into a fight with another man on a street in the Redwood Village area of San Diego, authorities said Sunday.
Volunteers turned out in force Saturday to participate in the I Love a Clean San Diego’s 16th Annual Creek to Bay Clean Up.