CHICAGO (CBS)– A fire in the back of an apartment building sent people out of their homes early Tuesday in the Old Town neighborhood.

Flames were seen engulfing the back porch on Hudson Avenue near Blackhawk Street.

A transformer explosion was initially blamed for the fire, but the Police and Fire departments later said the blaze started in a dumpster.

The flames lit up the alley at 2:30 a.m. Tuesday, as firefighters moved around dumpsters and garbage cans to put out the fire.

One neighbor shared cell phone video he shot of the fire from his back porch. Another neighbor posted Instagram video as the flames inched closer to her home.

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Update: No one was injured. One building is damaged and several cars were burned. The Red Cross was on the scene within 30 minutes handing out blankets, hand warmers, and other supplies. The CTA brought in a bus to be a warming station. The response time and thoughtfulness of these organizations was so appreciated. Woke up to the sound of small explosions, thought it was fireworks, opened my eyes, saw a glowing red light coming from behind the curtains. Went to the window and it wasn’t a small fire, the building across the alley was a roaring blaze. I called 911, was put on hold, and was told engines were on their way. At that point the fire was spreading rapidly and the cars in the alley were starting to catch on fire. I attempted to express how bad the situation was and that no one was on sight. I was told that the fire department knows what they are doing. Immediately after there was commotion in the halls and banging on my door. All my neighbors were up (thankfully). One was carrying his cat in a carrier (pet owners – keep those thing easily accessible!). I panicked and grabbed a bag and packed my laptop, a handful of underwear, and a change of clothing. Our power was out and I was running around using my phone as a flashlight. I joined my neighbors on the sidewalk. I called Charles who is in Boston and who actually answered. I rarely call him – so he knew something was up. After an hour outside the fire was out. The fire department does know what they are doing. I’m back home, safe, warm, and very thankful. We don’t have power and that might take a while since the telephone poles and power lines all burned. #chicago

A post shared by Kit Graham | Food+Travel Blog (@thekittchen) on

Other neighbors told CBS 2 they could feel the heat from the flames, inside their homes.

“We could feel the heat in the room, that if the glass was really hot by the touch, and as we’re trying to get our stuff on and get together, the heat was picking up in the room, so we knew we needed to get out immediately,” said neighbor Jeremy Brongiel.

The fire destroyed four cars and damaged several others, and also damaged several back porches.

(Credit: The Kitchen Is You/Instagram)

Credit: The Kitchen To You/Instagram)

According to Chicago Red Cross officials, two families were displaced and they will be provided with “immediate service.”

Firefighters late Tuesday were still trying to determine if the fire was linked to a series of recent arsons in alleys in the Lincoln Park neighborhood.