Officials received a call around 11 AM of a man struggling to stay afloat near the BU Bridge. The body was located after 1 PM.
Boston Fire Department divers and marine units worked alongside the Cambridge Fire Department and Mass State Police to find the missing man.
Dozens of first responders were on scene Wednesday afternoon.
According to WBZ-TV, two good Samaritans were the first in the water to help the struggling swimmer. They tried to help the man by borrowing a boat.
By the time they were able to reach him, he was already underwater.
This is a developing story, stay tuned to WBZ NewsRadio for the latest: