SUDBURY -- Early Tuesday evening, the Ontario Fire Marshall's office confirmed the Elm Street blaze was arson.

Original story:

Sudbury police say Elm Street has been reopened following what they call a 'suspicious' early morning fire at the Elizabeth Fry Society building.

Deputy Fire Chief Jesse Oshell told CTV News the call came in about 4:50 a.m. and firefighters from the downtown station were on the scene in under two minutes.

He said the fire started in the front of the building and spread up into the third-floor space.

Luckily, no one was inside the building at the time of the fire, but crews did a full search to ensure there was no one trapped inside.

Oshell said approximately 24 firefighters from five stations attended the blaze and they received many calls about smoke entering adjacent buildings. Crews were sent to clear out the smoke from neighbouring buildings and one person was taken to hospital as a precaution due to non-life-threatening injuries caused by the fire.

Despite the proximity of the neighbouring buildings, the age, and the type of construction, crews were able to contain the blaze to just one structure. It took about an hour to get the fire under control and declared it out 30 minutes later after pulling apart pieces of the building to get to the hot spots.

A collaborative investigation between Sudbury fire services, police, and the Ontario Fire Marshal is continuing to determine the cause.

The fire has been deemed suspicious.