TORONTO, Ontario (AP) — Two grandparents and their infant grandchild were killed on a highway east of Toronto when a van being chased by police crashed while going the wrong way, causing a six-vehicle collision, Canadian police said Tuesday.

The chase late Monday was triggered by an alleged liquor store robbery, and the crash also left the suspect in the chased van dead, police said.

The two grandparents, aged 55 and 60, and their infant grandchild were killed, and an additional person was injured and taken to a hospital, police spokeswoman Monica Hudon of the Special Investigations Unit, or SIU, told a news conference Tuesday.

The unit investigates any time a police officer has been involved in a serious injury or death.

Hudon said the SIU’s investigation was in “early stages,” and would look into whether police officers were authorized to continue chasing the suspected van onto the highway.

She also said police were still confirming the number of victims in the crash.