Tens of thousands of households lost power Sunday night in and around Long Beach’s coastal neighborhoods, including Bluff Heights, Alamitos Beach and Belmont Shore. Crews were still trying to restore power hours later.

The outage began at about 6:40 p.m., initially affecting 26,626, according to the Southern California Edison outage map.

The boundaries of the outage were:

West of Quincy Avenue

East of Alamitos Avenue

North of E Ocean Blvd

South of E 7th Street

As of 8:30 p.m., power had been restored to several thousand customers, but 22,066 households remained out, SCE spokesperson Diane Castro said.

At that point, there was no estimated restoration time available.

The cause of the outage was under investigation. The blackout arrived as much of the region remained under a high heat advisory.