A new, experimental hybrid bus called the EcoSaver IV is being tested in New York City. With a turbine for an engine, the bus virtually eliminates engine noise.

Hybrid engines that would be replaced are in buses that roll in the outer boroughs, where high-speed transit and less frequent stops are more common, Seaton said.

The buses are considered series hybrids, in which the diesel engine charges an electric motor, which drives the transmission.

Metro has pulled 164 buses — 10 percent of its fleet — from service for emergency inspections after two recent incidents in which the engines cut off suddenly while the buses were moving.

Bus 168 in the Iredell-Statesville school district. The engine of the bus, which was not carrying children at the time, caught fire last year.

(Olive Branch, MS) A school bus engine exploded at Church Road and Pleasant Hill, according to Olive Branch police. The students were all taken off the bus, and no one was hurt.

A roadway is clearing after a crash in northwestern Richland County involving a school bus and a fire engine on Thursday.

Dallas County North Texas students evacuated before school bus engine caught fire, district confirms DeSoto Independent School District said no one was injured.