MITCHELL — A mechanical issue at a NorthWestern Energy substation in Mitchell left an estimated 5,000 people in the Mitchell area without power Tuesday afternoon.

According to a NorthWestern Energy official, a blown transformer at a Mitchell transmission substation is what caused Tuesday’s widespread power outage. The mechanical issue left most of Mitchell customers without power for about 30 minutes over the noon hour.

Crews managed to repair the transformer at the substation shortly after the issue occurred, according to a NorthWestern Energy official.

During the power outage, traffic signal lights throughout much of Mitchell were down and many businesses closed. An estimated 4,682 NorthWestern Energy customers in Mitchell and the surrounding area were affected by the blown transformer at the substation.

NorthWestern customers as far south as Ethan and Dimock also lost power for a period of time.