Fire Chief Duane Estvold said the man killed was hooked to a harness and was partly submerged after the section of the Four Bears Bridge gave way about 10 a.m.
Estvold said another man appeared to have a broken leg, and two others suffered injuries to their pelvises. No names were immediately released, but Estvold said all four men were from the region.
``I helped load them into the ambulance,'' he said.
The three who were injured were taken to Minot's Trinity hospital, he said.
The 4,200-foot Four Bears bridge is to be the longest in the state when it is finished, and at $55 million the most expensive project undertaken by the state Transportation Department. It will replace a narrow, outdated bridge.
Gwen Lanzer, a spokeswoman for St. Louis-based Fru-Con Construction, which began work on the project in May 2003, said earlier that the company was trying to determine what happened.
Officials had said recently that the new bridge was 65 percent complete. It was scheduled to be completed next summer.
The site is in west-central North Dakota.
The bridge under construction has been the site of at least one other accident.
A Texas man was seriously injured June 26, 2003, when he was hit and knocked to the ground by a track that separated from a crane. The company said the man had to rehabilitate his shoulder, but did not release his name or any other details.The Federal Occupational Safety and Health Administration conducted a three-month investigation but found no rule violations.
