Power transmission lines run through Jacumba Hot Springs, March 9, 2021.

A series of power outages left thousands of homes and businesses without electrical service Friday in Normal Heights, North Park, and University Heights.

The first of the three blackouts began about 11:50 p.m. Thursday, according to San Diego Gas & Electric. The second hit shortly after 10:30 a.m. Friday and the third about 90 minutes later, the utility reported.

As of early Friday afternoon, a total of 2,935 addresses were without power in the three mid-city communities north of Balboa Park, according to SDG&E.

All the affected customers were back in service as of 3:15 p.m. Friday, according to the utility, which attributed the first two outages to “a need to repair SDG&E equipment.” The cause of the third was under investigation, the power company reported.