SALT LAKE CITY — A significant power outage left tens of thousands of people without electric service along the Wasatch Front before noon on Monday.

Rocky Mountain Power’s website showed the number of customers impacted by 1 p.m. to be in excess of 57,000. By 1:30 p.m., the number had dropped below 30,000. The utility reported that all service had been restored by 2 p.m.

Our crews are currently responding to multiple outages in Salt Lake Valley. The cause of the outages are still under investigation at this time. For continuous updates please visit us at https://t.co/siomLbq2r5

— Rocky Mountain Power (@RMP_Utah) April 9, 2018

Rocky Mountain Power later attributed the outage to a circuit breaker that “did not operate correctly” at the company’s Oquirrh substation near 6000 West Old Bingham Highway. In a news release, Rocky Mountain Power said the initial problem grew to affect seven substations in the southwestern portion of the Salt Lake Valley.

The widespread disruption caused delays at some busy intersections for a time, as traffic lights went dark or started flashing.

Driver alert: Power Outages in Davis, Utah & Salt Lake Cos. As the power is restored some signals will be in flash mode. Please treat dark/flashing intersections as 4-way stop. @sandycityutah @drapercity @CityWestJordan @SouthJordanUT @HerrimanCity

— UDOT Traffic (@UDOTTRAFFIC) April 9, 2018

The Utah Transit Authority also reported service impacts on the Trax red line during the noon hour.

TRAX Alert 12:32 pm: Due to a power outage, no train service is available from Jordan Valley – Daybreak on the Red Line. A van bridge has been activated at those stations. Expect Red Line delays.

— UTA (@RideUTA) April 9, 2018

UTA restored full service to the Trax red line shortly before 2 p.m. but warned residual delays might continue for a time.

In Davis County, the South Davis Metro Fire Agency noted several refineries were impacted by the power bump.

A power bump has caused several refineries to have extra flaring at their stacks. We are in contact with all the refineries and have verified the extra flare or large flares are due to the power bump.

— SOUTHDAVISMETROFIRE (@SDMFA) April 9, 2018

The Jordan School District reported on Twitter that the outage had affected several schools, but classes continued as normal.

Rocky Mountain Power said the outage was not a result of tampering or sabotage but an investigation was underway to determine the details.

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