A top paramedic says the fatal crash north of Toronto that killed 3 children and their grandfather 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.

He said on Friday it was "premature" to discuss how his client would plead.

Park says the eight paramedics who have taken time off were away all week and will likely need to take next week off as well so they can start to recover.

"I've never seen a case where we've had this number of paramedics affected," Park said.

A string of recent suicides among first responders has shone a spotlight on mental health issues among paramedics and law enforcement.

"As a profession, paramedics often feel that there's a stigma associated with it, they keep inside," Park said.

"When we have an incident like this, when we have so many [paramedics] that are affected, it gives us the opportunity to start talking about it," along with resources available to staff, he said.