The Windsor Fire and Rescue Service says Monday morning's fire in the 600 block of Mercer Street is considered suspicious.
As reported, crews were called to a two-storey house at the corner of Mercer and Wyandotte Street East just after 8 a.m.
As they battled the blaze, officials reported that part of the vacant structure had collapsed.
Damage is estimated at over $300,000.
The Windsor police arson unit were called in, however fire officials said the house was deemed unsafe to enter and they could not complete the investigation into origin and cause.
Anyone with information is asked to reach out to police or Crime Stoppers.