A top paramedic says the fatal crash that claimed the lives of three children and their grandfather north of Toronto has had an unprecedented impact on the well being of first responders.

Iain Park, deputy chief for York Region EMS, says eight of the 15 paramedics who attended the scene of last Sunday's crash in Vaughan, Ont., have taken time off to seek help for post-traumatic stress disorder.

He says that in his 25-year career, he has never seen a single incident affect so many staff members.

The deaths of Daniel Neville-Lake, 9, Harrison Neville-Lake, 5, Milly Neville-Lake, 2, and their grandfather Gary Neville, 65, have prompted a public outpouring of grief and sympathy.

Marco Muzzo, of King Township, Ont., faces a dozen impaired-driving offences and six charges related to the dangerous operation of a motor vehicle in connection with the incident.

His lawyer Brian Greenspan has said Muzzo, who is being held in custody pending a bail hearing on Oct. 19, is devastated by the tragedy.