A 22-year-old man was critically injured when part of a power line tower fell on him in Spanish Fork Canyon Thursday.

The man had been helping to build a high-transmission power line tower when part of it fell, trapping him for a time, Utah County Sheriff's Sgt. Spencer Cannon said.

Deputies and emergency medical personnel responded to the scene near Dairy Fork about 12 p.m. The man was taken to Utah Valley Hospital in Provo via medical helicopter.

"The folks that were with him gave really good information about his condition and exactly where they were so we were able to get right to where they were as quickly as we possibly could," Cannon said.

The portion of the tower that fell was around 20 feet long, he said, saying it was "much like an old erector set, except on a much larger scale.

"He was in pretty bad shape, in a lot of pain," Cannon said.

Deputies initially reported that the man was 20-year-old, but later said he was 22.

More information was not immediately available.

This story will be updated.

Contributing: Ladd Egan