BOSTON (CBS) – On Friday morning, emergency crews joined forces at MassDOT’s Highway Operations center to train for a fire in one of Boston’s tunnels.

In the training scenario, a truck was on fire in the Sumner Tunnel with three injuries, a traffic jam and a small busload of elderly folks stuck in it.

Drivers using the tunnel lost a lane for an hour or so, but first responders gained valuable knowledge on how to deal with the real thing.

The training scenario was similar to a truck fire that happened on New Year’s Eve.