PLUMERVILLE, Ark.—The great-grandmother of three boys who drowned in an Arkansas lake said Monday their mother missed a turn while traveling home after a night out with friends and plunged into the water from an unfamiliar road that had been converted into a boat ramp.

The local sheriff said the mother’s story has checked out so far and there was no indication of foul play.

In the aftermath of Sunday’s accident at Lake Brewer, the boys’ mother left town to seek funeral suits and well-wishers began erecting memorials at the water’s edge.

“We’ve lost our lives mostly,” said Margaret “Dean” Whatley, 71, of Plumerville. “It’s really more than we can handle.”

Investigators resumed interviews Monday to determine why Amber Turley’s car entered the water at the abrupt end of Johnny Walker Road. The road was Arkansas 92 until the early 1980s, when the route was moved a bit eastward to snake around man-made Brewer Lake.

At the end of a long downhill grade, motorists must make a sharp left to enter a parking area or follow the pavement to the lake. A warning sign directs motorists to turn left at the bottom of the hill.

“We don’t know why they haven’t had a barrier up there where the car went in,” Whatley said in a telephone interview.

Turley was driving home about 3:30 a.m. when she missed a turn that would take her to her home north of Plumerville. “She had been to visit friends. She’s 26. They don’t keep hours like we would,” Whatley said.

Even though the lake is just a few miles away, Turley wouldn’t have necessarily known she was on the road to the lake. “That wouldn’t have registered,” Whatley said.

Conway County Sheriff Mike Smith said Monday there was no reason to believe the deaths of Aaron Turley, 8; Alex Turley, 7; and Anthony Turley, 2; were suspicious.

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

The mother went shopping Monday seeking three-piece suits in which to bury the boys. “They looked darling in their little suits,” Whatley said.

According to the sheriff, Turley told investigators she was traveling home from a friend’s house and made the wrong turn. 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.

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