MINNEAPOLIS (WCCO) – Two workers spent much of Thursday evening trapped more than 100 feet up in a cell phone tower in Plymouth, Minn., after a harness malfunctioned, authorities said.

Shortly before 6 p.m., one of the workers called authorities, saying he was stuck on the tower, about 110 feet up in the air. The Plymouth Fire Department responded, and found the two workers, who had been performing maintenance.

The rescue, to which the Edina and St. Louis Park fire departments responded, took about two hours.

After, emergency crews brought the workers to North Memorial Medical Center for observation, considering the two had spent hours in the cold.

When they came off the tower, the workers were alert, authorities said.

Capt. Dave Dreelan, of the Plymouth Fire Department, said one worker’s harness malfunctioned, making it so he couldn’t get down.