Toronto police are mourning the death of one of their own after Const. John Zivcic succumbed Monday to injuries that he suffered in a weekend crash that occurred as he was responding to an emergency call about an impaired driver.

Deputy Chief Peter Sloly made the announcement outside St. Michael's Hospital in Toronto on Monday. He said Zivcic died just after 12:30 p.m. surrounded by members of his immediate family.

"He died in the line of duty doing his job, trying to keep the public safe," Sloly said.

Zivcic, 34, was being treated for severe head injuries after his unmarked police vehicle was involved in a collision Saturday afternoon near Bloor Street West and Neilson Drive.

Police said the officer — who had been with the force for more than six years — was on traffic duty responding to a call when the crash occurred. He had multiple surgeries over the weekend before succumbing to his injuries Monday. The driver of the other vehicle had minor injuries.

A few hours after police announced that Zivcic had died, a news release said that arrangements were being made for the officer’s organs to be donated.

"It’s a terrible day for the Toronto Police Service," said Toronto Police Association president Mike McCormack.

"Our hearts are broken for John’s family."

The officer is survived by his mother, as well as his brother and sister and their spouses.

On Monday evening, the Canadian flag stood at half-mast at 22 Division, the west-end police station where Zivcic had worked since the start of his policing career. A book of condolences has been set up at the station, where fresh flowers and notes of thanks have been placed.

The crash occurred just a few kilometres away from the station.

Toronto police issued a photo Monday showing a smiling Zivcic on the day of his police graduation. Later, a second photo was released showing the smiling officer in a blazer and tie.

As the news of Zivcic’s death spread on Monday, fellow officers tweeted condolences to his family in the wake of his death.

“He worked very hard and that’s why we have to support front-line police men and women. They sacrifice their life day in and day out and it’s a very sad day today," said Ford.

Premier Kathleen Wynne also issued a statement of condolence on Monday.

"For the past seven years, Const. Zivcic has given his best to his colleagues, to his city and to the people of Ontario. We owe him an immense debt of gratitude for his sacrifice."

Zivcic, who was originally from St. Catharines, Ont., was described as a “greatly respected guy,” specifically at 22 Division.

A statement issued by police said officials are working with the family on making funeral arrangements.

"The [Toronto Police] Service and the Toronto Police Association are here to support the family as they move forward in this process and to support our officers as they grieve the loss of John," read the statement. "We will issue an update when details are available.

"Again, we thank the public and our policing family for their support. We will continue to focus our attention on supporting the family."

Police are saying little about what may have caused Saturday's crash, which is under investigation by traffic services.

Another vehicle was involved, but Zivcic’s cruiser also crashed into a tree and he was said to have been ejected from the vehicle.

Traffic collisions have claimed the lives of several on-duty Ontario officers in recent years, including an officer in Peel Region three years ago and a young Guelph officer earlier this year.