Police are at the scene of a triple fatal crash north of Listowel. (Courtesy: OPP)

OPP say following a lengthy investigation they have charged a man in connection with a crash that killed three Londoners near Listowel.

An SUV and tractor trailer collided at the intersection of Perth Line 88/Fordwich Line and Perth Road 178, north of Listowel on June 21.

Police say 60-year-old Walter Yetman, 58-year-old Donna Yetman and 28-year-old Stephanie Roloson were pronounced dead at the scene.

A two-year-old boy had non-life threatening injuries.

Police say the driver of the tractor trailer failed to stop for a stop sign at the intersection.

Gurvinder Singh, 38, of Brampton has been charged with three counts of causing death by criminal negligence.