PUEBLO, Colo. (AP) — Interstate 25 in southern Colorado is expected to reopen Thursday, four days after the main north-south route through the state was shut down when a train derailment caused by a broken rail collapsed a railroad bridge onto the highway and killed a truck driver, Gov. Jared Polis said Wednesday.

Polis toured the damage near Pueblo on Wednesday with local leaders and representatives with the National Transportation Safety Board. He also offered condolences to family and friends of Lafollette Henderson, the 60-year-old truck driver from Compton, California, who is survived by six children and 15 grandchildren.

The steel bridge, built in 1958, collapsed Sunday when 30 cars from a BNSF Railway train hauling coal derailed while crossing over I-25. Investigators are examining how the rail broke and why warning systems did not alert crews to the condition of the track, according to the NTSB.

A 9-mile (14-kilometer) stretch of I-25 — used by 39,000 to 44,000 vehicles daily — was shut down as crews cleared hundreds of tons of spilled coal and mangled railcars from the roadway. Traffic was being detoured around the derailment site and through the town of Penrose, almost 30 miles (48 kilometers) west of Pueblo.

The southbound lanes of I-25 were being repaved Wednesday and were expected to open later in the day. Crews were working to open the northbound lanes by Thursday evening.

“Our top priority is to get the highway back open so that people can continue traveling safely between Colorado Springs and Pueblo, and the rest of the state,” Polis said, adding that “it remains clear that investments in rail are needed now more than ever.”

Pressure for the railroad industry to improve safety has intensified since a February derailment of a train hauling toxic chemicals that triggered evacuations in Ohio and Pennsylvania. There were more than 12,400 train derailments in the U.S. in the past decade, or more than 1,200 annually, according to Federal Railroad Administration data based on reports submitted by railroads.

At least 111 railroad accidents have been caused by bridge failures or bridge misalignments since 1976, according to an Associated Press review of derailment reports railroads submitted to the Federal Railroad Administration. That’s just over two accidents annually on average.