VENTNOR, N.J. — The longtime location of the Sack O’ Subs sandwich shop was damaged Saturday evening by a three-alarm fire next door, only eight days after its reopening following an abrupt change in ownership.

Three families were displaced and received help from the American Red Cross, officials said.

As investigators combed the scene Sunday morning on the 5200 block of Ventnor Avenue, a bulldozer began demolishing the long-shuttered U-Mango smoothie and bubble tea shop that adjoined Sack O’ Subs, which was now closed.

”I’m just sick to my stomach over what has happened,” said Anthony Sacco, who bought the Sack O’ Subs shop from franchisee Fred Spitalnick earlier this month.

Spitalnick abruptly closed Sack O’ Subs after business on Memorial Day. Sacco — whose grandfather Anthony “Fuzzy” Sacco opened the business in 1969 and who also operates the Sack O’ Subs shop in Absecon — reopened the Ventnor store on June 10 after a cleanup.

Shortly before 6 p.m. Saturday, patrons and staff at adjacent businesses, including moviegoers watching Lightyear and Jurassic World Dominion at the Ventnor Square Theatre and customers at Nucky’s Kitchen & Speakeasy, were evacuated as flames shot from the roof of U-Mango.

Three families in apartments above the businesses were displaced, said Michael Cahill, chief of Ventnor City Fire Department. Companies from Atlantic City, Margate, Longport, and Brigantine also responded.

Cahill said there were no injuries and the cause of the fire was under investigation.

Sacco said he was unsure of his next steps until a building inspector visits the property. “This has been a roller-coaster of emotions for me,” he said.

Brett DeNafo, owner of the Ventnor Square Theatre, said the art deco theater, which dates to 1938 and reopened last summer after a multimillion-dollar restoration, seemed to have been spared damage and could reopen.

On Sunday afternoon, the Shore town’s busy block still smelled of fire, and the third of the structure that had been the smoothie shop was a demolished heap of building material. The windows above Sack O’ Subs were broken, and the remaining top frame of the building was scarred black from fire.

Next door, though, Nucky’s was back open, with people sitting at the bar, as were the movie theater and Mr. Gordo’s, the restaurant on the other side of Sack O’ Subs.