Work on the indoor practice facility near Jack Trice Stadium ceased Wednesday afternoon when part of a crane arm collapsed onto a construction worker.

Leslie Johnson, known as “Les,” was part of a three man crew taking apart the boom, or arm, of an American 60-ton lattice boom crawler crane Wednesday afternoon, said Mike Tousley, president of Weitz Co. The men were disassembling the boom at the joint, which was about head-level to the men.

About 15 to 20 other workers were on the job site, Tousley said.

A section of the boom was being removed and replaced with a shorter piece, which would be used to pick up a section of steel Thursday morning, Tousley said.

Part of the crane apparently hit Johnson, 47, on his left leg, pinning him underneath, said John McCarroll, director of university relations.

The university and Weitz officials said they were notified of the accident around 1:30 p.m.

Within minutes, workers had lifted the section of the boom off of Johnson’s leg, Tousley said. The next couple of minutes were spent stabilizing Johnson.

Johnson, who is from Omaha, Neb., was not an employee of the Weitz Co., but an employee of subcontractor J.P. Cullen & Sons, based out of Janesville, Wis. J.P. Cullen & Sons was subcontracted to be the structural steel erection firm for the building construction.

Johnson was transported to Mary Greeley Medical Center, 1111 Duff Ave., and his family was notified, McCarroll said.

David Cullen, vice president of J.P. Cullen & Sons, said he believed Johnson fractured his leg, but it was unconfirmed as of Wednesday afternoon.

“Our thoughts are with Leslie to make sure he’s doing as well as expected,” Cullen said.

McCarroll said he believed Johnson was conscious when he left the job site, but in pain.

“All of the workers said [he was] in a lot of pain,” he said.

The accident is currently under investigation, Tousley said. All safety precautions were being taken at the time, and weather was not a factor, he said.

McCarroll said no other workers were injured.

“The operator [of the crane] was shaken up,” he said.

Tousley said Weitz Co. has had one other accident involving a crane.

In 1994, an incident occurred at the downtown Des Moines Principal building site, Tousley said.

Work at the construction site ceased after the accident occurred, he said.

“Anytime something like this happens on a job, it’s hard to go back to work,” Tousley said.

Johnson was in fair condition and was transferred to a hospital in Omaha, Neb. or Council Bluffs Wednesday night, an official of Mary Greeley Medical Center said.