TORONTO -- Canadian officials identified the suspect in Sunday's mass shooting as Faisal Hussain, 29, of Toronto. The attack in Toronto's Greektown district left two people dead and 13 others injured.

Authorities said Hussain died after an exchange of gunfire with officers. It was not immediately clear whether he killed himself or was killed by police.

Police said an 18-year-old woman and a 10-year-old girl were killed. The injured ranged in age from 10 to 59, and suffered injuries ranging from serious to minor, Police Chief Mark Saunders said Monday.

Hussain's family issued a statement saying they are "at a terrible loss for words" but needed express their condolences to victims' families.

Get Breaking News Delivered to Your Inbox Click here to view related media. click to expand

"We are utterly devastated by the incomprehensible news that our son was responsible for the senseless violence and loss of life that too place on the Danforth," the statement said. It said Hussain suffered "severe mental health challenges, struggling with psychosis and depression his entire life. The intervention of professionals were unsuccessful."

Police investigate the scene of a shooting from the night before in Toronto on July 23, 2018. Usman Khan/AFP/Getty

The 18-year-old victim killed was identified as Reese Fallon, a recent high school graduate who volunteered for Canada's Liberal party and was to attend McMaster University in the fall. Her family said in a statement they were devastated.

"She was ... smart, passionate and full of energy. It is a huge loss," said Canadian Member of Parliament Nathaniel Erskine-Smith, who knew Fallon.

Witnesses heard many shots and described the suspect walking past restaurants and cafes and patios on both sides of the street and firing into them.

Ontario's police watchdog said there was an exchange of gunfire between the assailant and two officers on a side street before the gunman was found dead near Danforth Avenue where the shootings occurred..

A spokeswoman for the Special Investigations Unit, Monica Hudon, said an autopsy would be performed Tuesday on the suspect.

Det. Sgt. Terry Browne said police had sought a search warrant for an address related to the suspect but didn't say where.