LONDON, ONT -- A cyclist is fighting for their life after being struck by a box truck near Port Ryerse south of Simcoe, Ont.

Norfolk County OPP have closed down Radical Road between Highway 24 and Port Ryerse Road following the collision shortly after 8 a.m.

Police say that the cyclist was traveling eastbound on Radical Road when they were struck by a box truck, also eastbound.

The cyclist was ejected and suffered serious life-threatening injuries.

They have since been airlifted to hospital for treatment.

Police say Radical Road will be closed for some time while they investigate the crash.