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.

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.

The attack shattered a sense of safety for parents and dancers from Seattle’s Kalahi Philippine Dance Company, who attended the heritage festival Saturday.