On Labor Day 1985, fire leveled 18 factories and 23 homes in the City of Passaic.
The disaster crippled the local economy, destroying businesses and putting more than 2,000 people out of work.
Police arrested two boys, ages 12 and 13, for starting the the blaze at the Gera Mills Industrial Park on Sept. 2, 1985.
''They have admitted to setting the fire,'' Passaic Mayor Joseph Lipari said at a news conference at City Hall. ''They stated they were playing with matches.''
Passaic firefighters were crippled by a lack of water, staffing shortages and antiquated radio communications and relied on mutual aid from from across North Jersey.
A member of the Secaucus Fire Department, William Koenemund, 65, suffered a fatal heart attack.
Koenemund, described as "100% fireman" by a chief officer, was working the ladders when he took ill, the Hudson Reporter said.
Eleven other firefighters were injured.
In a story marking the 25th anniversary of the disaster, NorthJersey.com said:
Investigators traced the fire's source to an alleyway between two six-story factories at 122 and 130 Eighth St., where two boys tossed matches into a refuse bin containing naphthalene, a highly flammable chemical used to make mothballs. Once lit, the fire spread rapidly between buildings and from one side of the street to the other.
Fueled by chemicals stored in some of the Eighth Street factories, the fire spread quickly, consuming six industrial buildings. Low water pressure from hydrants and a strong wind compounded firefighters' troubles extinguishing the blaze on the particularly warm day. More than 100 hydrants in the area had been shut to prevent people from opening them to cool off during the summer.
In addition, a 100,000-gallon water tank that fed firefighting appliances had sat empty and inoperable for at least two years before the fire.
In all, 300 firefighters from 39 departments worked for 12 hours to control the blaze, which smoldered for weeks.
Products that burned included paints, chemicals, solvents, postage stamps, vinyl wall coverings, cardboard boxes, yarn, handkerchiefs and polyester cloth, The New York Times reported, as well as costumes stored in a warehouse for the New York City Opera.