Pacific Power says it is investigating the cause of a power outage Wednesday that affected about 60,000 customers from Crescent City to Grants Pass.

Customers lost power about 3 p.m. and the outage lasted for about 20 minutes, according to utility spokesman Tom Gaunt. The outage was caused by a temporary loss of transmission, he said, but workers don’t know why transmission was lost and so they’re “looking into that.” There was no physical damage to the utility’s infrastructure, Gaunt said.