Two people, including a grandmother and a father, are dead after their canoe capsized on Marion County's Halfmoon Lake. Family members said it appears to be a practical joke that went wrong.

Five people were in the canoe when it capsized around 6:30 p.m. Sunday, according to the Florida Fish and Wildlife Conservation Commission. Only three of them survived.

Two brothers headed out on Halfmoon Lake on Sunday afternoon in canoe with their mother, 51-year-old Lisa Gibson, and two girls, ages 5 and 7.

But family members said one of the men jokingly tried to scare Lisa Gibson by rocking the boat. That's when it started to take on water.

When the 16-foot-long canoe capsized, Todd Gibson, the father of the girls, worked to keep them afloat.

"David swam to shore, and he turned around and saw them struggling," said Don Gibson, the victim's grandfather. "David went back and got the two girls from him and that's the last David saw of him."

Another boat was in the same area of the Ocala National Forest.

"They thought it was maybe just some people over here having a good time," said Greg Workman, spokesman for the Florida Fish and Wildlife Conservation Commission. "But it just didn't sound right, so they were able to come over here and immediately help with the rescue."

The two girls, David Gibson and Lisa Gibson were rescued and taken to Munroe Regional Medical Center.

The girls were released. Lisa Gibson died at the hospital.

Sheriff's Office helicopters circled the perimeter of the lake Monday looking for any signs of the missing boater while dive teams and boats with sonar searched below the surface of the mucky, 17-foot-deep lake.

The search ended around 2 p.m., when divers located 29-year-old Todd Gibson's body.

As officials searched the lake, they weren't able to find any sign of life preservers.

"They should have had one, and they should have had one for each person in the vessel as well," Workman said.

Don Gibson said he's thankful for good Samaritans, who helped his grandson save his great-granddaughters. But right now, the tragedy is tough to take.

"You aren't supposed to lose your (grandson)," he said.