A man who decided to stretch his legs forced the MBTA to shut the Blue Line around 5:50 p.m. when he got down on the tracks at Aquarium and began walking towards Maverick.

The T shut power and Transit Police cops and T inspectors started moving into the tunnel from both directions. The guy made it more than halfway under the harbor when the first cop approached him. He refused to go quietly, so police tased him, after which they were able to get him out of the tunnel and into a cruiser for a trip to booking at Transit Police headquarters on Southampton Street.

Among those who found themselves on a newly unmoving Blue Line train: Boston's Leslie Knope, who reported:

Our conductor just announced that someone is on the tracks at Aquarium, which is why we aren't moving.

And she asked passengers on the platform to "be careful and don't fall in?"

The MBTA reported at 6:36 p.m. that service was resuming, with residual delays.