DUNGEON MASTER!

Gilgo Beach suspect dug hidden chamber where police fear he committed murder

SUSPECTED Gilgo Beach serial killer Rex Heuermann lived in a terrifying house of horrors — complete with a dank homemade vault — where police and neighbors fear victims were tortured and killed!

As cops searched the ramshackle Massapequa Park, N.Y., home and dug up the grounds in a frantic hunt for clues and bodies, evidence emerged suggesting at least one young woman as well as scores of innocent animals may have died in a sound-deadened concrete vault.

Terrified Long Island neighbors tell The National ENQUIRER they often saw hulking Heuermann working on mysterious construction projects in his garage, but no one ever knew what he was doing or had the courage to ask.

Neighbor Frankie Musto reveals she saw Heuermann "building something" in the garage the weekend before his July 13 arrest for the decade-old murders of three sex workers.

Meanwhile, one of the 59-year-old suspect's co-workers says Heuermann took time off from his job as a Manhattan architect to install a heavily reinforced vault in his home, where cops found some 300 guns.