One side of the O'Neill Tunnel, carrying Interstate 93, was briefly shut in Boston on Wednesday, just before the evening rush, because of a vehicle fire.
It wasn't immediately clear if anyone was hurt. One lane of I-93 north reopened prior to Exit 17, according to the Massachusetts Department of Transportation.
Footage from the scene showed police and firefighters in the tunnel, apparently focused on a towed generator, and a Department of Transportation spokesman said that video appeared to show that a trailer being towed was what caught fire, citing video they shared from the scene.
It wasn't immediately clear how the item was involved or how it caught fire.
Traffic was heavily backed up heading into downtown Boston.
It's the third car fire in the tunnel in as many weeks. Two separate incidents within three days closed the tunnel in late August. There was no indication of any connection between the incidents.
