Updated, 12:25 a.m.
For the second day in a row, Boston and Cambridge firefighters and State Police responded to the Massachusetts Avenue bridge on a report of a possible jumper, only to find no evidence on the bridge or in the water that somebody had actually jumped.
Firefighters used thermal imagers and sonar to search the water, after the report of a possible jumper mid-span came in shortly before 11:50 p.m.
The bridge was shut in both directions. Around 12:20 a.m., Boston firefighters began packing up and leaving.