A woman whose car plunged off a dead-end road into a lake in rainy, dark weather told investigators she tried to rescue her three young sons from the vehicle but lost her grip on them in the water, a sheriff said Monday.

Conway County Sheriff Mike Smith said there was no reason thus far to suspect foul play in the deaths of Aaron Turley, 8; Alex Turley, 7; and Anthony Turley, 2. He said their mother's story has checked out, but that the investigation is ongoing.

"Right now, there is nothing that indicates it was done intentionally," Smith said.

The boys' mother, 26-year-old Amber Turley, told investigators she was driving home from a friend's house and made a wrong turn, Smith said. The weather was bad Sunday morning, with heavy rain and fog.

"She 'made a wrong turn' was her statement," said Smith, while also noting that she lived nearby and was "pretty familiar with the area." Turley also told investigators that she tried to get the boys out of the car but lost her grip, Smith said. Failing in the rescue attempt, she ran to a nearby home and called 911.

Smith has declined to say whether deputies conducted a field-sobriety test on the mother or drew any of her blood after the crash.

Turley's grandmother, Margaret "Dean" Whatley, said her granddaughter missed a turn at the abrupt end of Johnny Walker Road, which was a state highway until the early 1980s, when the route was moved a bit eastward.

At the end of a long downhill grade, motorists must make a sharp left to enter a parking area. A warning sign directs motorists to turn left at the bottom of the hill but the road itself goes straight to the edge of the lake, where there is no other warning sign.

"We don't know why they haven't had a barrier up there where the car went in," the 71-year-old Whatley said by phone.

Smith said many people in Conway County, about 30 miles west of Little Rock, use the old highway to back boats into the lake, which is a state wildlife management area. The reservoir serves as the main drinking water source for the nearby city of Conway.

The car was pulled from the water Sunday and was stored at a garage at the sheriff's department.

Relatives gathered Monday at a home in rural Plumerville.

"It's a terrible loss. This is a terrible thing," Larry Hopkins, who identified himself as the boys' grandfather, said through tears at the house. He then asked a reporter to leave, saying he didn't want to discuss the deaths.

Whatley said the boys' mother went shopping Monday for three-piece suits in which to bury them.

"They looked darling in their little suits," Whatley said.