The Ontario fire marshal has been called in to investigate a fire that broke out at the Petview store at Queen and John streets.
The two-alarm blaze broke out just before 3 a.m. on Friday.
The 501 Queen streetcar had to be diverted but has since returned to regular service.
Apartment buildings above the store were evacuated, and a TTC bus was brought in to provide temporary shelter to the residents.
There are reports a suspicious person was spotted near the scene at the time the fire broke out.