Xcel officials say faulty equipment is likely to blame for the power outages that left as many as 24,000 customers in northern Colorado without power Sunday evening and Monday morning. According to the Greeley Tribune: A piece of equipment at the Xcel substation in Greeley, at 10th Street and 23rd Avenue, failed in both instances. It’s not clear what piece of equipment failed. 17,000 customers in the Greeley, Evans, Garden City and LaSalle areas had no power for two hours Sunday and about an hour Monday morning. Also, customers as far east and west as Keenesburg and Lafayette were affected by the outage.

Power Outage, Flickr Grand Wickes

North Colorado Medical Center reported that some surgeries were postponed early Monday as the hospital went on emergency power. No other patients were affected by the outages.

Greeley police got several calls about the outage on Monday, including one about people stuck in the elevators at the Weld County Courthouse.