SAN DIEGO — Thousands of San Diego Gas & Electric customers were without power after an unexpected outage began shortly before 9 p.m. Sunday.

According to the utility company’s outage map, approximately 3,435 customers were affected in the communities of Logan Heights, Mountain View and Lincoln Park.

Power has since been restored to some of those customers. As of 11:15 p.m., 1,342 are still without electricity.

SDG&E expects the power to be completely restored by 4:30 a.m.

It is unknown at this time what caused the outage, but SDG&E said it has crews headed to the site of the issue.

This comes as the first leg of another storm has begun moving through the region. Strong winds and heavy precipitation are expected to set in Tuesday, bringing conditions that could prompt additional power outages.