SALISBURY, N.C. — A substitute bus for Hanford Dole Elementary School had to stop at the Miller's Ferry Fire Department Monday afternoon after a student became sick on the bus, according to Rowan-Salisbury Schools.
The school district said the bus had been on the route for about 10 minutes when it happened.
As the bus made it to the fire department, two other students on board said they were feeling sick. The two students were taken to be evaluated at an area hospital, and the remaining students were moved onto another bus for the rest of the bus route.
It comes just days after a similar incident happened on a bus for the same school. Friday, eight students and a bus driver were taken to a nearby hospital to be checked out after a "medical emergency" onboard led the bus driver to pull over at the fire department.
“We’re still puzzled as to what’s causing it," Rowan County Emergency Services Chief Allen Cress said.
He's been working alongside the district and says the sick students tested positive for carbon monoxide.
"They shouldn’t be exhibiting any levels… unless they were exposed," Cress said.
The search for answers has lasted days, with leaders testing the buses, the school, and even the homes of students for carbon monoxide, but Cress said they still haven't found the source.
“There’s no readings on either bus, inside the school, their homes," Cress said. "No readings there."
Jay Helson gave some insight into the process investigators may be pursuing.
He's been repairing large vehicles like buses and motor homes for more than 30 years at his Charlotte business Carolina Auto Truck and Coach Service.
“Carbon monoxide and a vehicle -- we’d have to study hard on the exhaust, and look at the maintenance records," Helson said.
The school district said it is working with "several groups" to investigate the issue, adding that the district's director of transportation tested the bus involved Monday as soon as he arrived and the test had a zero carbon monoxide reading.
The district said the bus from Friday was tested while at the fire department that day, and it tested at a zero carbon monoxide level as well.
Rowan-Salisbury Schools said two staff members, including the transportation director, rode the bus route Tuesday afternoon and found no carbon monoxide using a certified meter.
"On Friday, March 24, bus 372 was used to transport students from their homes to Hanford Dole Elementary in the morning with no issue. We are looking at all potential causes both before students boarded the bus to leave Hanford Dole and while on the bus while en route," the district said in a statement. "We will conduct a 30-day inspection as a precautionary measure. Additional evaluation will be conducted on both buses. We will conduct additional idle testing and testing while running the bus route. We are working with county safety officials to evaluate any potential exposures at the school site prior to the bus departing the school."
As the investigation continues, the district adds that all students have been released from the hospital.