MEMPHIS, Tenn. — An interstate bridge crossing the Mississippi River at Memphis, Tennessee, remained closed Wednesday after inspectors found a crack in the span a day earlier.

The Interstate 40 bridge linking Arkansas and Tennessee was shut down Tuesday afternoon after the crack was discovered during a routine inspection, the Arkansas Department of Transportation said.

The department said it was working with the Tennessee Department of Transportation to ensure the 48-year-old, 1.8-mile (2.9-kilometer) bridge is safe before reopening.

Traffic was being rerouted to the 71-year-old Memphis & Arkansas Bridge that carries Interstate 55 into Memphis, about 3 miles (4.8 kilometers) south of the I-40 span. River traffic was also shut down until further notice, the Tennessee Department of Transportation said.

In an inspection for the 2020 National Bridge Inventory report, the Federal Highway Administration said the I-40 bridge checked out in fair condition overall, with all primary structure elements sound and only some minor cracks and chips in the overall structure. Its structural evaluation checked out “somewhat better than minimum adequacy to tolerate being left in place as is.”

However, height and width clearances for oversize vehicles were “basically intolerable requiring high priority of corrective action,” the inspectors found. Tennessee recommended “bridge deck replacement with only incidental widening.”

The bridge, which opened in 1973, carried a 2020 average of 35,000 vehicles a day across the Mississippi River, 29% of them trucks, according to the report. Its traffic volume was expected to increase to 56,000 vehicles per day by 2040.