A spokeswoman at Baylor University Medical Center in Dallas said one person was in critical condition and the other two were in fair condition.
The three workers were wearing protective safety equipment, said Jack Hill, director of stadium construction for the team. They all work for subcontractor Derr Steel Erection, which did not immediately respond to a phone message.
The more-than-$1-billion retractable-roof stadium is scheduled to be finished about a year from now and will seat 80,000 people.
It also will be home to the 2011 Super Bowl.
Thursday's accident came one day after a crane hook plummeted to the ground in Dallas after a cable snapped, killing a worker at a condominium project.
(Copyright 2008 by The Associated Press. All Rights Reserved.) AP-NY-06-12-08 1952EDT T
