Firefighters from Byram, Hopatcong and Stanhope reported to the 7 a.m. fire at 48 Main St.
Michelle Koller-Vega posted a series of videos showing smoke billowing from the building before it collapsed.
One person was reportedly hospitalized for smoke inhalation, the NJHerald reports.
A couple living on an upper floor of the three-story building is receiving assistance from the Red Cross to provide housing.
The Netcong Laundromat and Drycleaners was located on the bottom level and one of the two commercial units on the second level was for rent.
The House of Gold Salon next door was also destroyed by the blaze, according to a GoFundMe launched by Jess Dworniczak. The campaign had raised more than $2,000 as of Monday morning.
The cause remains under investigation.
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