Update, 1:27 a.m.:
PSE is reporting that power has been restored to all but a few hundred customers, and the lights should come on by morning.
A PSE update after 1 a.m. said 254 customers were still without power.
Nearly 6,000 homes and businesses on Mercer Island were without power Saturday night after an outage.
According to Puget Sound Energy (PSE), the outage struck around 8:45 p.m. According to PSE’s website crews expect to have power restored to nearly 3,000 customers by 11 p.m. The remaining customers are expected to have power back by 3 a.m.
PSE says the cause of the outages is under investigation.