One person is dead, and five others are seriously injured after a fire broke out at a Toronto Community Housing highrise in Scarborough on Saturday afternoon.

Toronto Fire said crews responded to a two-alarm fire in a unit on the 5th floor of an apartment building in the area of Kingston Road and Lawrence Avenue East shortly before 3:30 p.m.

When crews arrived, they were met with heavy smoke. A CP24 viewer tweeted a video showing black smoke billowing out of the building.

"Our crews made very quick entry into the building both for search and rescue and interior attack operations. They were able to very quickly control the fire and then had to deal with the migration and smoke issues," said Toronto Fire Chief Matthew Pegg.

During the search and rescue, a number of residents were located inside the building, and one of them was pronounced dead, Pegg said.

"On behalf of all of us at Toronto Fire Services and, of course, Toronto Police, we extend our most sincere condolences to the friends, the family and all those impacted by this terrible loss at this tragic fire."

While Pegg said there were four other injured residents who needed to be hospitalized, Toronto paramedics told CP24 that they transported a total of five people.

One of them, a woman in her 60s, has life-threatening injuries. The four others, including a man in his 60s and two women in their 60s, are in serious condition.

"The fire has now been extinguished. Our crews are continuing to work on the scene," Pegg said.

The cause, origin and circumstances of the fire are unknown.

"Far too early for us to tell. We won't speculate on that. That investigation will continue in due course," Pegg said.

When asked if the person who died was an occupant of the unit where the fire was, the fire chief said he didn't have that information.

"The status of all of the occupants and the circumstances that lead and contributed to this tragic fatal fire will, of course, form part of the investigation," Pegg said.

Toronto Fire investigators and Ontario's Office of the Fire Marshal have been notified.

Scarborough fire

Pegg noted that the building was a subject of a routine fire code inspection last month.

"That’s standard process for us. Toronto Fire Services inspects all high rise, residential buildings and all Toronto Community Housing buildings at least once a year," he said. "There were no significant issues and no issues with the fire code, which is good. But, of course, all of that work will also be included in the investigation."

The fire displaced an unknown number of residents. Pegg said Toronto Community Housing and the Toronto Transit Agency had made arrangements for emergency shelter.

Several TTC buses are on the scene to temporarily house the affected residents.

"For those that are displaced from the building here today, it's going to be some time until we can sort through what'swhat's happened here," Toronto police Duty Insp. Jason Albanese said. "So we ask for patience and your understanding until we unravel what's happened here."

Crews remained at the scene early Sunday morning performing fire watches.