Police believe arson may be the cause behind a two-alarm fire near the DVP and Highway 401.
Firefighters were called to 150 Graydon Hall Dr. just after 1 a.m. after a tenant on the fourth floor noticed smoke in their unit and called 911.
Police say part of the building was evacuated in the blaze and several people were treated for smoke inhalation.
No arrests have been made and police would not say why they suspect arson was the cause of the blaze.
