A power outage in the Uptown area briefly left about 4,400 customers without service Friday afternoon, SDG&E reported.
The outage was reported in Hillcrest, University Heights, Mission Hills, Normal Heights and North Park area at about 2 p.m.
By about 4 p.m., power was restore, according to SDG&E's website.
The outage came in the middle of a heat wave, as usually high temperatures throughout San Diego have many switching on their air-conditioners.
SDG&E suspects the problem was caused by overhead electrical system problems. It is not yet known whether the outage had anything to do with the heat.
Traffic signals were black from 7th and University Ave. to about 11th and University Ave.
The cause is still under investigation.
Check back for more information on this developing story.