A second Greenbrier teen has died and two more received medical treatment after officials said they drank a mixture of Mountain Dew and racing fuel last week.

On Thursday, authorities were called to the Franklin Farms home of 16-year-old Logan Stephenson, who was found dead in his bed.

Within minutes, they were called to a second home, on Cemetery Road, because the boy’s best friend had begun having seizures, Greenbrier Police Chief K.D. Smith said.

“We ask that everyone continue to pray for both of these families as they go through this tragic time,” Sheriff Bill Holt said in the department’s Tuesday release.

Since Stephenson’s death, two other teens have come forward, claiming they drank a similar substance, Smith said.

Four cases from Robertson County have been recorded with the Tennessee Poison Center at Vanderbilt University Medical Center, according to medical director Dr. Donna Seger.

Two of the teenagers were treated and released from two different emergency departments, Seger said.

Both teens said they had consumed a mixture of Mountain Dew and racing fuel, she said.

“They thought they knew what it was, that it was a substitute for alcohol,” Seger said. “They thought they would get the same effects as alcohol, but they weren’t aware of how toxic it was.”

Racing fuel, used in drag racing, is made up of almost 100% methanol, a non-drinkable form of alcohol used for industrial and automotive purposes, Seger said.