MCKINNEY, Texas — First responders are currently attempting to rescue the driver of a truck, which is hanging off the side of an overpass on Highway 121 above Hardin Boulevard, which is part of Sam Rayburn Tollway.

Video from Chopper 8 shows the truck hanging over the bridge with multiple firefighters working to extract the driver from the vehicle.

The North Texas Tollway Authority says all southbound lanes of Sam Rayburn Tollway at Hardin Boulevard have been closed due to the crash. Two northbound lanes of the tollway have also been closed.

Drivers in the area should expect heavy delays.

This is a developing story; please check back for updates.

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