Police in central Florida say an alligator attacked a homeless man who was swimming in a river. Melbourne police Cmdr. Dan Lynch tells CBS affiliate WKMG the "alligator came up and grabbed" the man in the Indian River in Brevard County. He says officers were training in the area Monday morning when they heard the man screaming. The 56-year-old man, who was swimming, was bitten on the shoulder by a gator that Melbourne police said was "definitely a big one." "The officers heard the screaming and found him on the bank of the river with significant gashes on his shoulder. We found him there on the shore," Lynch said. The man was conscious but in pain when medics arrived to take him to the hospital. He is expected to survive, police said. Wildlife officials were called to the scene to search for the gator.