ST. PAUL, Minn. - A bridge over the Red River along the North Dakota-Minnesota border has been closed after an inspection prompted by the Interstate 35W bridge collapse found a crack in a support bracket.

Transportation departments in both states said the bridge was closed Tuesday night. It is known as the Robbin Bridge along State Highway 11 in northwestern Minnesota and as the Drayton Bridge on North Dakota Highway 66. Officials said a crack was found in a support bracket for a girder.

Bob McFarlin, an assistant to the Minnesota transportation commissioner, said that in May, inspectors found a crack in a weld that joined two pieces of steel - a finding that wasn't serious enough to close the bridge. Tuesday, however, inspectors found that the crack had spread a few inches into the steel bracket.

The crack is in an approach near the North Dakota side of the bridge, McFarlin said. No one was in danger, he said. About 1,400 vehicles drive over the bridge every day.

MnDOT's state bridge engineer, Dan Dorgan, said the crack was in a spot where, even if the cracked piece had failed, it likely would not have caused the bridge to collapse.

"Even if you lose the outside girder, your main load is in the middle of the bridge," where the three main support girders were in fine shape, Dorgan said.

The 1,058-foot long truss bridge, which is 53 years old, was not scheduled to be inspected again until April next year at the earliest. It was scheduled for replacement in 2009.

Gov. Tim Pawlenty ordered the inspection of state bridges after the Aug. 1 I-35W bridge collapse, which killed 13 people and injured about 100 more.

Les Noehr, a district engineer for the North Dakota Department of Transportation, said representatives from both states were looking at the bridge Wednesday and discussing repairs.

Noehr said he doubted the bridge replacement schedule would be moved up.

"It doesn't look like that will be necessary at this point," he said.

The bridge is used by trucks hauling sugar beets to area processors. In December, it was damaged by a semitrailer hauling a load of farm equipment. Officials said then that the load exceeded the height of the bridge trusses on the Minnesota side of the river. The bridge also is in an area prone to spring flooding.

"There's a whole host of things, certainly just use, weather," Noehr said, of the factors that might have contributed to the crack.

The bridge likely will be closed for several days, officials said.

On the Minnesota side, motorists can cross the river at state Highways 317 or 175. On the North Dakota side, drivers can take Highway 5 or Highway 17.

"I'd rather have them inconvenience people now and fix whatever the problem is instead of having a repeat of the I-35 in the cities," Ken Hultgren, the county sheriff on the Minnesota side, told KFGO-AM radio in Fargo, N.D.