PORTLAND, Ore. (KOIN) — Lightning is believed to be the cause of a major blackout in Clark County early Tuesday morning.

Dameon Pesanti, a spokesperson for Clark Public Utilities, told KOIN 6 that Monday’s lightning storm kept crews busy as they worked to replace 18 transformers across the area.

The utility company reported the storm knocked power out just before 12:30 a.m.

The outage, which left more than 11,000 people without power at one point, was fully restored by 6:30 a.m., according to Clark Public Utilities.

Shortly before being restored, about 9,200 homes in northeast Vancouver, toward Mill Plain, were in the dark.

The outage map at one point listed more than 27,000 customers had lost power, but Pesanti attributed that to a glitch in the system which “registered a blink during the transmission work as an outage.”