Generators at three power plants tripped off-line Saturday night triggering the power outage that affected about 63,000 customers on the Big Island, according to a news release from the Hawaii Electric Light Co.

The Hawaii Electric Light Co. said generators at Hamakua Energy Partners in Honokaa, HELCO’s Keahole plant and the HRD wind farm in Hawi unexpectedly went off-line at about 8:37 p.m.

The sudden loss of generation led to the automatic shut off of electricity to various locations, a HELCO spokesman said.

Additional generators were started and power was restored to all customers after the Hamakua Energy Partners and Keahole power plant returned to service at 9:37 p.m.