CINCINNATI (WDTN) — The Brent Spence Bridge on the border between Ohio and Kentucky will be closed in both directions for at least the rest of the day Wednesday after a massive semi-truck fire and chemical leak, officials said.

WLWT reported authorities said the explosion happened after two trucks collided in the northbound lanes on the lower deck of the bridge around 2:45 a.m. When officers arrived at the scene they discovered both semi-trucks engulfed in flames.

Investigators were able to locate both drivers. Neither were injured, officials told WLWT.

The fire and damage to the bridge caused officials to also shut down the southbound lanes on the upper deck of the bridge.

WLWT reported the fire burned for around two hours before crews were able to put it out. Covington Fire Chief Mark Pierce told WLWT one of the trucks was carrying 110 pounds of potassium hydroxide and a large amount of diesel fuel, causing the bulk of the fire.

Pierce said the potassium hydroxide won’t have an impact on anyone in the area and most of it has been diluted with water.

Bridge inspectors and EPA officials have responded to the scene to determine what caused the crash and how much damage has been done to the bridge. “We have to eliminate all possibilities. We have to err on the side of safety,” Pierce told WLWT.

Police are advising everyone to avoid the area while they inspect the damage.

“We are expecting the bridge to be closed for an extended period of time. At this point we are projecting today at a minimum,” Assistant Chief of Police Brian Valenti said. River traffic in the downtown area has been shut down as well.

The Brent Spence Bridge is a double-decker truss bridge that carries Interstates 71 and 75 across the Ohio River, connecting Cincinnati and Covington, Kentucky.