A deadly blaze that killed three people in a two-family Queens house at 42-38 65th Street, and revealed the numerous unregulated apartments divided within, has drawn a keen eye toward the growing problem of illegal apartments in the five boroughs. Following the fire, officials found that the Woodside home had as many as five different living units in its basement alone, and six more crammed into the upstairs space. One family lived in its unit in the house for two years before the blaze revealed the scheme. Housing advocates say that many other illegal apartments exist throughout the city, but that they’re difficult to track down and that they often hide in plain sight. Some experts say that as many as 100,000 illegal apartments currently exist in the city, the New York Times reported.