Taylorsville, IN – TAYLORSVILLE, Ind. – Children from a Kentucky church were hospitalized after their bus filled with what authorities suspect was carbon monoxide, officials said.

Indiana Fire Marshal Roger Johnson said seven children from the Evangel World Prayer Center were taken to Columbus Regional Hospital Sunday night after they became sick during a 240-mile ride from Merrillville to Louisville, Ky.

Hospital spokeswoman Denise Glesing said five people were treated in the emergency room and released overnight. Another child was taken to Johnson Memorial Hospital, said Bartholomew County Sheriff Department spokesman Mark Gorbett.

“We can assume it was carbon monoxide poisoning at this point,” he said.

A seventh child, who was removed from the bus hours earlier in northwest Indiana’s Jasper County, was in serious condition at a hospital there, Johnson said.

“It’s probably somewhat of a blessing that … more people weren’t overcome by the fumes,” Johnson said.

The bus with 30 passengers returning from a track meet stopped at a rest area 40 miles south of Indianapolis around 10:30 p.m., after a 14-year-old on board complained of breathing difficulties, Johnson said.