Authorities say the man was seen speaking on a cell phone near the river shortly before he fell in late Wednesday morning. It wasn't immediately clear if the man slipped and fell into the river or was stricken with some kind of medical problem.
Some witnesses who saw the man pulled him from the river and reported he was not breathing, but authorities say paramedics performed cardiopulmonary resuscitation and were able to get the man's heart beating before he was taken way in an ambulance.
The man's name and condition have not been released. It was not immediately clear whether he was a convention center guest.