Two men on a speeding ATV tumbled into a lake at night south of the Twin Cities and were killed, authorities said.

The Le Sueur County Sheriff's Office was alerted about 4:30 a.m. Thursday to the incident in Lake Sakatah in Waterville Township, about 15 miles southwest of Faribault.

Found submerged in the water were the bodies of Zachary R. Paulson, who turned 18 on Tuesday, of Kilkenny, Minn., and Derek M. Brandvold, 24, of Waterville, the Sheriff's Office said.

Sheriff David Tietz said his office has determined that the crash occurred about 45 minutes to an hour before the bodies were found.

The vehicle was traveling on Sakatah Lake Road on the northern edge of the body of water, when the two "lost control [and] were ejected from the ATV and landed" in the lake, a Sheriff's Office statement read. The ATV remained on dry land, Tietz said.

Tietz said there are "indications that speed was involved" when the ATV went out of control. He added that neither man had on helmets, which could have lessened the trauma the two suffered.

There were "no obvious indicators" of alcohol being a factor in the crash across from Kamp Dels, said the sheriff, who added that autopsy results were pending.

Tietz said investigators have yet to determine who was operating the ATV.