LOWELL -- Firefighters pulled an unidentified man from the swollen and fast-flowing Merrimack River downtown yesterday afternoon just after the man apparently jumped from the Cox Bridge.

Police and firefighters scrambled to the bridge about 2:15 p.m., for witness reports that a man was dangling from the bridge before he fell into the water.

Luis Pedraza, who lives in the Massachusetts Mills apartments next door said he didn't see the man jump, but saw the man a short time later in the water on the downtown side of the river as people encouraged him to swim to the river bank.

"A lady on the bridge was yelling to the guy, 'swim to the trees, swim to the trees,'" Pedraza said. "We couldn't tell if the guy went under the water or up into the trees, he just disappeared."

It turns out the man had made it to the trees, though, firefighters said.

The crew of the city's Ladder 3 fire engine arrived at the scene from the central fire station downtown, got down near the water and used a 'life ring' and rope to pull the man onto dry land, according to a deputy fire chief.

That quick action kept firefighters from using their rescue boat, which was about to be launched, the deputy said.

There was some concern about hypothermia, so the man was taken to Saints Medical Center by Trinity Ambulance, the deputy said.

Firefighters did not get the man's identity, and a police report on the matter was not completed last night so police could not provide additional information.

The river has risen about 2 feet in the last two days, and is now flowing rapidly about 5 feet below flood stage, according to the National Oceanic and Atmospheric Administration, which monitors its flow.

The river is not expected to rise further though, according to predictions provided by the agency online.

Sun reporter Jennifer Myers contributed to this story.