COLTON (CBSLA.com) – Lightning strikes caused major outages in Colton Thursday that left thousands of people in the dark and forced several schools to close for the day.

A lightning strike hit the main substation for Colton Electric Utility, which knocked out power and phone service to about 50,000 customers, according to Colton Public Utilities. Colton’s population is at around 53,000.

READ MORE: One Killed In Palmdale Hit-And-Run; Authorities Searching For Suspect

The city was asking residents to conserve water because its pumps did not have power. Repairs were expected to take until at least 4 p.m. Power has since been restored to Arrowhead Regional Medical Center and several parts of the city. It was unclear how many customers were still without power.

Cooling centers were opened at the Hutton Center at 660 Colton Ave., Gonzales Center at 670 Colton Ave., Luque Center at 292 East O St. and Paul J. Rogers Auditorium at 955 West Laurel St.

As a result of the outage, Colton Joint Unified School District canceled classes at the following schools:

READ MORE: LASD Seeks Help Locating 26-Year-Old Abraham Miguel Aguiniga Who Suffers From Schizophrenia

— Rogers, Grant, Lincoln, Birney, Mckinley, Cooley, Reche, Grand Terrace and Wilson elementary schools.
— Colton and Terrace Hills middle schools.
— Colton and Washington high schools.
— San Salvador preschool.

Classes were expected to resume as scheduled Friday.

CEU has its own power plant and four separate substations which service about 16,000 residential and 2,500 commercial customers, according to its website. The substation struck by lightning is run by Southern California Edison, but works with CEU.

MORE NEWS: Bystander Struck By Bullet In Downtown LA Shooting On Tuesday