Public access to the old Rock Island Swing Bridge that once connected Washington and Dakota counties was closed Monday, just days after a portion of the bridge collapsed.

Dakota County installed signs Monday on the west approach, at Inver Grove Heights, to stop pedestrians from walking onto the bridge. Marathon Oil Corp. now owns the approaches on the Washington County side, which has no public access. The east and west spans aren't connected because the swing portion in the middle is locked open to allow barges to pass.

Both counties had intended to remove the bridge in 2010, but Don Theisen, Washington County's chief engineer, said Monday that he considered the bridge a hazard that needs urgent attention. It will be discussed at today's Washington County Board meeting.

A 200-foot piece between two columns on the Washington County side of the Mississippi River was found fallen to the shore Friday, Theisen said.

"The rest of the structure isn't in any better shape," he said. "It's not like Dakota County's side is any better."

Removal of the deteriorating bridge that once ferried automobiles and trains across the river has been discussed for years. Most recently known as JAR Bridge, the double-decker structure was closed to trains in 1980 and vehicle traffic in 1999. The bridge was built in 1894.

Washington and Dakota counties inherited the bridge when it went into tax forfeiture after several years of private ownership.

"We've known that the bridge is in poor condition for nine years," said Mark Krebsbach, Dakota County's transportation director. "That's why it's been closed to traffic. Engineering studies on the bridge have indicated it's in very poor condition, but there was nothing that said there was any imminent failure pending."

John Weeks, a bridge historian from Burnsville, said that he has seen Minnesota Department of Transportation photographs that show metal on the bridge corroded to the point that people can push their fingers through it.

"It might be a bridge too far gone to save," he said.

But Paul Labovitz, superintendent of the 72-mile Mississippi National River and Recreation Area, thinks the collapse could provide the opportunity for "pause and think this through," including whether part of the bridge could salvaged as a lookout.

Last month, National Park Service rangers gave tours and a program about the bridge.

"The bridge is interesting from an engineering perspective," Labovitz said. "It is maybe the only one of a kind left in the country. ... And apparently, there's a lot of local stories. People have all kinds of experiences with this bridge." • 651-298-1554 • 612-673-7750