The main north-south highway in Colorado is expected to remain closed for several more days as crews clear piles of coal and other debris after a weekend train derailment and bridge collapse, authorities said Tuesday.

Federal investigators approved cleanup work after largely completing their evidence collection where the BNSF coal train derailed onto Interstate 25 north of Pueblo, Colorado, killing a truck driver.

There is no reason believe the derailment was sabotage, said Sarah Taylor Sulick, of the National Transportation Safety Board.

The bridge, built in 1958, collapsed when 30 cars from the train derailed Sunday afternoon, the NTSB said. The 60-year-old driver of a semitrailer truck that was passing beneath the bridge was killed.

Officials said the derailment caused the bridge collapse but have not said what caused the derailment.

A preliminary report from investigators is due in several weeks.

“They will be pulling maintenance records. They’ll be interviewing people involved. They’ll be talking to the railroad. They’ll be talking to the state,” Sulick said.

A nine-mile (14-kilometer) stretch of I-25 — used by 39,000 to 44,000 vehicles daily — was shut down. Traffic was being detoured around the derailment site and through the town of Penrose, almost 30 miles west of Pueblo.

Meanwhile, the bridge’s ownership remained unclear two days after the accident.

Railroad companies typically own the bridges that trains use. However, BNSF said the steel girder bridge that collapsed onto I-25 was owned by the state.

Colorado officials initially said the bridge was the property of the railroad but later backed off that claim.

Officials were still combing through records Tuesday, trying to determine ownership, said Matt Inzeo, of the Colorado Department of Transportation.

Hundreds of tons of coal and mangled railcars that landed on I-25 were expected to be cleared from the road by Wednesday afternoon, officials said. After that, officials will be able to assess how badly the road is damaged and what repairs are needed.

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 submitted by railroads to the Federal Railroad Administration. That’s just over two accidents annually on average.

President Joe Biden had been scheduled to visit a wind energy company in Pueblo the day after the accident but postponed the trip at the last minute to focus on the growing conflict in the Middle East.

Sunday’s accident follows a railroad bridge collapse in June along a Montana Rail Link route in southern Montana that sent railcars with oil products plunging into the Yellowstone River, spilling molten sulfur and up to 250 tons (226.7 metric tons) of hot asphalt. The accident remains under investigation.