UPDATED: Cranford Fire Department Helps Extinguish Westfield Blaze (Video, Photos)

The Cranford Fire Department responded to a stubborn home fire in Westfield Monday evening. The cause of the three alarm fire, which kept firefighters on seen past midnight, remains unknown.

Firefighters arrived at the two family home located at 591 Westfield Avenue responding to a call at 6:54 p.m. to a fire in the residence. Firefighters saw the back of the home engulfed in flames upon arrival. Seven towns, along with Union County fire officials responded to the scene.

The fire was not under control for several hours, with flames shooting out of the back of the home at random times, including 8:45 p.m. and 9 p.m. Westfield Fire Chief Dan Kelly said the building's construction, which includes a two story extension in the rear, has many void spaces, which hampered firefighters. The firefighters could not respond in the interior of the building because of the concern with the stability of the floors, leading the fire to be fought from the exterior, which delayed the operation. At one point, firefighters were called to evacuate the house.

No injuries were reported to either firefighters or civilians. The extent of the damage is unknown, but Kelly said damage was seen on both floors of the house.

Kelly said the cause of the fire remains under investigation. He said widespread reports at the scene, that propane tanks on the back deck were to blame, had yet to be confirmed by fire officials.

One eyewitness said the fire appeared to start with an explosion. Tony Loviscek, who was working next door, said he heard some people shouting.

"There was an explosion. I heard two explosions," he said.

Loviscek said when he turned to look at the house, flames were shooting out of the windows and the back porch was on fire. He said he called 911 to report the fire. A contractor working in another adjoining house also reported the fire to 911.

Kelly confirmed that there was a grill on the back porch of the building, which contained propane tanks. He said the grill was not in use when the fire broke out.

Kelly said that the building's one occupant at the time of the fire, a man in the first floor apartment, escaped the building through a window, finding the doorways blocked by flames. This is contrary to early reports at the scene, where the building owner said three people and one cat were in the building at the time of the fire. Kelly confirmed that two other individuals, one other in the first floor apartment and one in the second floor unit, live in the house but were not home when the fire occurred. Kelly could not confirm the whereabouts or safety of any cat who lived in the house.

A couple who confirmed they live in the house declined to comment about the fire. They appeared shaken by the incident and were being comforted by Red Cross volunteers.

Olivier Delaurteniis is the owner of the building, but does not live on-site. During a brief interview with Patch at the scene, he said he was not sure of the extent of the damage but said it appeared that the fire may have started in the kitchen adjacent to the back porch.

The fire, one of the largest in town this year, brought fire departments from Westfield, Clark, Garwood, Scotch Plains, Fanwood, Roselle and Mountainside, along the rescue squads from Westfield, Fanwood, Scotch Plains and Springfield. One firefighter said approximately 50 firefighters were on scene at one point, with approximately 10 fire trucks dottting Westfield Avenue and surrounding streets.

A large crowd formed early accross Westfield Avenue to watch the scene unfold. At one point power was cut to power lines in front of the house to better allow fire fighting to continue. People in the crowd were buzzing about the fire jumping to nearby buildings. While firefighters inspected neighboring buildings it appeared unlikely the fire would spread. The crowd thinned around 8:30 p.m. but continued to gain new people.

A large cloud of smoke could be seen coming from the house long after the main flames had been extinguished. According to observers the smoke could be smelled in downtown Westfield.

Editor's Note: Lindsay Wilkes-Edrington and Neil Hodge contributed to this report.