A school bus driver was killed Tuesday morning when her bus hit the shoulder of a roadway and veered into a tree, according to police.

Middlesex OPP said the yellow school bus was travelling near London, on Twelve Mile Road, when it struck the shoulder of the roadway.

The bus then careened across the road, striking a tree, and rolling onto its passenger side.

The 63-year-old female driver, who was alone on the bus, was pronounced dead at the scene.

No other vehicle was involved.

Police are withholding the driver’s identity until next of kin are notified.

Twelve Mile Road was closed between Highbury Avenue and Adelaide Road at around 10:00 a.m. while police investigated.

The road was re-opened early Tuesday afternoon.