Hundreds gathered in Toronto on Tuesday afternoon to mourn the loss of two pilots and two paramedics killed in an Ornge air ambulance crash last month.

Capt. Don Filliter, First Officer Jacques Dupuy, and fight paramedics Dustin Dagenais and Chris Snowball were killed when an Ornge helicopter crashed following takeoff from Moosonee, Ont.

Premier Kathleen Wynne and Health Minister Deb Matthews were among those who attended Tuesday's memorial service.

The helicopter had just left its base at the Moosonee airport to pick up a patient in the remote Attawapiskat First Nation when it crashed early on May 31.

Ornge took its five remaining Sikorsky S76 helicopters out of service for several days as a precaution.

Transportation Safety Board officers investigating the crash have said mechanical failure did not appear to be the cause.

With files from The Canadian Press