CHICAGO -- Chicago Police Department arson detectives were investigating a suspicious fire Saturday in which two men died on the city's Southwest Side.
Sources tell WGN all signs point to arson. A bomb sniffing dog detected an accelerant, some kind of gas or substance that fanned the flames.
The fire spread rapidly while the two men were trapped inside. Shortly before 10 a.m., neighbors noticed the blaze at the 5200 block of South Lorel and recorded it on their cellphones.
It was a massive blaze. Smoke consumed the house, billowing up from the roof. Some 90 firefighters and paramedics responded. But they were overwhelmed. There was too much smoke and heat for the first responders to enter, so firefighters used a deck-gun to blast the house with water.
Then, they tried to ventilate the residence before using a sledgehammer to get in.
Authorities say they believe the victim on the first floor was a 63-year-old male. The person upstairs they believe was a 26-year-old male.
Both men died before first responders could reach them. Officials say there were no working smoke detectors inside the house.
A source close to the investigation indicated this could have been gang related. Police are very familiar with this home; they were called here around 4 a.m. this morning.
Neither of the victims has been officially identified.
-- The Chicago Tribune contributed to this report.