GOLDEN VALLEY, Minn. (WCCO) – A Twin Cities hospital was without power for 90 minutes Tuesday night, forcing Regency Hospital in Golden Valley to evacuate some patients.

The outage caused the hospital to go on emergency battery back-up at about 6 p.m. with 55 patients inside the building.

Four patients needed to be transported to other hospitals.

“When you have patients on respirator, when you have patients on monitoring, it all takes electricity,” said John Allen, Regency Hospital CEO. “We took steps to make sure no patient was harmed. No patient was put at risk.”

A blown fuse outside of the building may have played a role in the outage.