Sacramento authorities are investigating a drowning at the American River. Sacramento Fire Captain Dave Whitt says a 40-year-old homeless man drowned in the river yesterday, the fourth such incident in area rivers in six days. The victim disappeared into the water for five to 10 minutes before being pulled out by Sacramento police officers patrolling the area in a boat. C.P.R. was started immediately, and the man was taken by ambulance to Sutter General Hospital, where he was pronounced dead. Heraldo Gonzales, a friend of the victim, says that the two of them had come to Sacramento three weeks ago looking for work and were staying in shelters and churches. There were two drownings on Saturday and a near-drowning on Thursday.