Orange County Sheriff's Department officials said the victim was thrown into the swimming pool after the suspects stole items from his home.
Authorities believe the victim's home in Villa Park was chosen randomly by two suspects.
"We believe the suspects thought the home was unoccupied and they surprised the victim," said Jim Amormino of the Orange County Sheriff's Department.
The 65-year-old victim was recovering from recent abdominal surgery when two men entered through an unlocked sliding door in the back and ransacked his home.
"The shorter suspect went upstairs, came down asked the victim if there were additional property, then struck the victim two times with a closed fist in the stomach area--the same area he just received surgery," said Amormino.
Investigators said the men mainly stole jewelry. One suspect then punched the victim several more times.
"This time he forced the gentleman into the backyard, punched him in the back and pushed him in the swimming pool," said police.
Authorities said the victim did not know how to swim, but managed to make it to the side and to a neighbor's house to call for help.
One of the suspects was described as a Hispanic male, 20 to 30 years old and 6 feet tall. He was skinny with a brown and black shaggy beard. He was wearing a black T-shirt and a white beanie.
The other suspect was described as a male Hispanic in his 30s, 5 feet 8 inches tall and 250 pounds. He was wearing a white T-shirt and a black beanie.
As investigators search for suspects, they urge residents to lock windows and doors.
"Making sure my front windows are closed. But we have a dog, so if they come into the house they're going to be surprised," said Ron Govea, a neighbor.
The victim was treated at his home and then taken to his family doctor. His exact condition is unknown.
Authorities said the suspects left in a white pickup truck, possibly a Chevy. They said the truck matches the description of a getaway vehicle used in at least two other burglaries in Tustin over the last few weeks.
Anyone with information related to the case was urged to call Orange County Sherriff's Department at (866) 847-6273.
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