An off-duty York Region police officer described as a "tireless humanitarian" was one of three people killed in a fiery two-car crash early Saturday morning north of Toronto.

Const. Davis Ahlowalia, 28, joined the force 2 1/2 years ago. He worked out of the Newmarket detachment.

The accident occurred on Major Mackenzie Drive west of Pine Valley Drive in Vaughan at about 3:30 a.m.

Police said the driver of a Dodge Caravan travelling west lost control and crossed the centre line, striking a Honda Civic being driven by Ahlowalia. Both vehicles erupted in flames after the impact.

Heavy fog may have played a factor in the head-on collision, which happened near Woodbridge. Major Mackenzie between Islington Avenue and Pine Valley was expected to be closed for much of Saturday.

Ahlowalia was remembered as an enthusiastic and dedicated police officer.

"Davis had a warm heart. He was a humanitarian, with excellent people skills and a disarming sense of humour .... with the dedication to bring goodness to anything he touched," stated a press release.

"Davis was a committed member of the community who worked tirelessly to make life better for those less fortunate, including the elderly, the disabled and the homeless. Davis did more for others in his 28 years that most people do in a lifetime."

The officer travelled to Jamaica or India each year, spending his vacation time working with poverty-stricken families and those suffering from HIV/AIDS. He was the "driving force" behind the force's campaign to raise funds for a Jamaican orphanage.

"This is truly a tragedy that someone so young, with so much to give, is gone," stated Chief Armand La Barge.

"We extend our deepest sympathy to Davis' many friends and family and we will be supporting them in their time of grief."

Ahlowalia, who lived with his mother, always had a smile on his face, his brother told CTV's Jim Junkin.

Ahlowalia considered becoming a priest, but instead felt he could make more of a difference as a police officer.

Detectives on Saturday said the two passengers in the minivan who died were teenage boys. Their identities were not released until family members were notified. Identification was difficult as the bodies were severely burned.

A third passenger in the van, also a teenage boy, managed to escape the wreckage. He was taken to Sunnybrook Hospital with life-threatening injuries. His identity has not been released.

"We don't have any witnesses to this collision, again, this happened at 3:30 this morning and any witnesses or anybody with information, we'd really appreciate your call," Sgt. Dave Mitchell told reporters.

Contact police at 1-866-876-5423 ext. 7703 or Crime Stoppers at 1-800-222-TIPS (8477). Information can be left online at www.1800222tips.com.

With a report from CTV's Jim Junkin