What caused two CMS buses to burst into flames? Here’s what investigation found.

After weeks of investigation, Charlotte-Mecklenburg Schools has concluded that wiring in the engine compartment probably caused two buses to catch fire while making runs this fall.

The report was quietly posted this week, amid news of snow closings.

“CMS and (North Carolina Department of Public Instruction) inspectors were unable to positively identify a specific cause but did feel that the area around the starter could be an area of concern,” the statement says. “CMS transportation staff looked for missing frame insulators and condition of the wiring; even though some of these buses did not have frame insulators when new. Transportation teams have taken the proactive step of installing this protective sleeve on any bus identified as a concern.”

In October a bus taking students home from South Mecklenburg High caught fire, forcing 16 students to evacuate near a busy intersection. In November a bus headed toward Olympic High for an afternoon pickup also burst into flames after the driver smelled smoke.

Both were Cat 3126 Freightliner Thomas Built buses, and were both spares that had been pulled into service. They’re among 259 in the CMS fleet of more than 1,400 buses, which includes regular, spare and activity buses, and about 3,000 taking North Carolina children to and from school.

CMS launched its investigation after the second fire, and state officials urged re-inspection of all such buses, saying they’re known for risk of engine fires.

This story was originally published January 19, 2018 at 5:39 PM with the headline "What caused two CMS buses to burst into flames? Here’s what investigation found.."