TEWKSBURY (CBS) – An accident involving three tractor-trailers caused a massive traffic tie-up on Route 495 north Wednesday morning.

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The trucks crashed just before the exit to Route 133 in Tewksbury around 5 a.m.

There were no serious injuries reported, but one truck went off the road down into a ditch.

One of the trucks was carrying empty paint cans.  Another was hauling rice.

Traffic was backed up for miles at the start of rush hour because only one lane of vehicles was getting by the scene.

There’s no word yet on what caused the crash.