A fire at an abandoned house in the eastern part of the downtown core last weekend which injured two firefighters called to douse the flames is now being treated as arson, with police circulating a composite sketch of a male suspect.

Fire crews were called to the three-floor house, at the corner of Jarvis and Shuter streets, at 2 a.m. on Nov. 2.

Firefighters said at the time the flames had largely engulfed the building, preventing them from conducting a search of the inside. It reached a three-alarm response.

Two firefighters who were attempting to ventilate the building by opening up its roof later fell nearly the full height of the structure while attempting to move onto a ledge.One broke his leg while the other suffered more serious injuries.

The Toronto Professional Firefighters’ Association (TPFFA) says that one of its members, Capt. Jim Warren, remains in the intensive care unit at St. Michael’s Hospital as a result of his injuries but is now awake and alert.

“His breathing has greatly improved, and he is talking. At one point today they had him standing up for a few minutes.  He tires easily and he is still in intensive care. He will be downgraded within the intensive care unit in the next day or two and hopefully moved to a recovery room within the next week,” TPFFA President Frank Ramagnano said Thursday.

After a thorough search of the wreckage, the Ontario Fire Marshal’s office says the blaze was caused by arson.

Police said Thursday that witnesses spotted a man leaving the structure as fire crews arrived.

A sketch of that man was released on Thursday.

Anyone with information is asked to call police at 416-808-5100.