Three workers were critically injured after falling from a workover rig at a site operated by Exco Resources in rural north-west Louisiana.
A fourth worker was injured in the fall but sustained only minor injuries, according to a statement from the DeSoto Parish Sheriff's Department. The accident occurred in Kingston, Louisiana, on Friday morning just before 10:00 local time.
One of the three critically injured was flown to a hospital in Shreveport, Louisiana, the Sheriff's office said.
Local reports said the four workers were walking on a catwalk when it collapsed. They reportedly fell some 30 feet to the rig floor. No reason has been given for the equipment malfunction.
Exco did not respond to a request for comment.
First responders told broadcast news station KSLA that the fourth man "rode the piece of equipment" to the ground before jumping off, saving himself from more serious injury.
"The report on scene is he actually rode the piece of equipment that broke loose and right before it hit the ground, he jumped off," DeSoto Fire Captain Dallas Niette said. "That saved him a whole lot of pain and agony."
The conditions or the identities of the injured workers were not know on Tuesday.