Vancouver police ruled out terrorism as a motivator for the incident at the Lapu Lapu Day Festival, saying the suspect has a history of mental health issues.

A driver plowed a car into a crowd at a street festival celebrating Filipino heritage in Vancouver on Saturday night, killing at least 11 people and injuring dozens more in what police are calling “the darkest day” in the city’s history.

A 30-year-old Vancouver man was arrested at the scene and the department’s Major Crime Section is overseeing the investigation, police said.