The Interstate 495 bridge over Christina River was ordered to an emergency closure in Wilmington after the four columns supporting the bridge were discovered to be tilting on Monday, NBC News reported.
Drivers should be prepared for a delay along I-95, the alternate route, since officials aren't certain of when the bridge will reopen.
Transporting about 90,000 vehicles on a daily basis on I-495, the 4,800-foot bridge diverts traffic around the city of Wilmington and toward the Port of Wilmington. The route parallels Interstate 95, which runs through downtown Wilmington.
"We understand that there will be a significant impact to the traveling public," said state Transportation Secretary Shailen Bhatt.
However, he remained uncertain of how long the bridge will be closed off to drivers.
"It could be significant amount of time," he said.
The four columns on the south bank of the river are tilted by as much as 2.4 degrees, or 4 percent, from vertical, officials said.
Until the cause of the shifting of the columns and what needs to be done to address it is not determined, the bridge will be closed in both directions.
"The whole bridge will be re-inspected," said Rob McCleary, chief engineer for the Delaware Department of Transportation.
Engineers are hoping to unearth clues that will help them determine how to shore up the bridge over the Christina River, a process officials say is going to take considerable time, the Associated Press reported.
"Anything that's buried is a lot more difficult to deal with than anything that's above ground," noted Bhatt.
"This is a really serious situation that we're very lucky we caught in time," Bhatt added. "We don't know what could have happened. We're going to take every step to make sure things are safe before we reopen."
A collapse, however, was not believed to be imminent, the transportation department chief engineer confirmed.
"We never said that it was ready to fail. We were concerned about the tilt because that was abnormal behavior for that structure," Rob McCleary said.
