A fuse failure during a period of high electrical demand knocked out power to roughly 500 customers in Billings’ Annafeld subdivision for about six hours on July 11, NorthWestern Energy has confirmed — and the utility initially gave the wrong explanation for what went wrong.

What Happened

The outage began around 4:20 p.m. Saturday and was not resolved until shortly after 10 p.m. The Annafeld subdivision is supplied through a substation with two underground distribution feeds, and crews had to reconfigure distribution equipment to rebalance the electrical load across both feeds before power could be restored.

The outage came as Billings was baking in extreme heat. Temperatures in the city hit 111 degrees the following day, making the loss of electricity — and with it, air conditioning — a significant concern for affected residents.

Company’s Initial Explanation Was Wrong

NorthWestern Energy initially told customers the outage was caused by a vehicle striking a power pole at around 4:45 p.m. That explanation turned out to be incorrect. The utility later acknowledged it had mixed up two separate outages: a vehicle crash that caused a different outage on July 10, and the fuse failure in the Annafeld area on July 11.

The mix-up meant the company publicly attributed the wrong cause to the wrong event during the initial response, leaving affected customers with inaccurate information during a six-hour outage in dangerous heat.

Residents Describe Overloaded System

At least one resident reported that a NorthWestern Energy worker on the scene described the electrical system as overloaded, with crews working to shift customers between the two distribution feeds to balance demand. That account aligns with the utility’s subsequent explanation that system load needed to be redistributed before power could be safely restored.

NorthWestern Energy has not publicly detailed what specific conditions triggered the fuse failure, though the company characterized the outage as occurring during a period of high electricity demand — a description consistent with the intense heat gripping the region that weekend.

Broader Grid Pressure

The Billings outage illustrates the strain that prolonged heat events place on electrical infrastructure across Montana. Sustained high temperatures drive up residential and commercial cooling loads, increasing stress on distribution equipment that may not have been engineered for the demand levels now seen during extreme weather.

NorthWestern Energy serves a large share of Montana’s electric customers and has faced ongoing scrutiny over grid reliability and rate structures. Infrastructure resilience during peak demand periods has become a recurring concern for state regulators and lawmakers as the region experiences more frequent and severe heat events.

The Public Service Commission, which oversees NorthWestern Energy’s rates and service obligations in Montana, has the authority to examine outage causes and utility response times, though no regulatory action related to this event has been announced.

What’s Next

Power has been restored to the Annafeld subdivision, and NorthWestern Energy has corrected its public account of the outage’s cause. It is not yet clear whether the utility plans to conduct a formal review of the fuse failure or take any steps to reinforce distribution capacity in the area ahead of future high-demand periods.

With temperatures in Billings reaching 111 degrees the day after the outage, residents and local officials are likely to watch grid performance closely through the remainder of the summer. Extended heat waves stress not just individual components like fuses, but entire distribution networks — raising questions about whether Montana’s utility infrastructure is keeping pace with changing climate conditions.

For now, NorthWestern Energy has not issued additional advisories about system capacity or conservation requests for the Billings area.