BOSTON — Italian casual dining chain Bertucci’s has filed for Chapter 11 bankruptcy protection and closed 15 restaurants.

Fifty-nine locations in 10 states and Washington remain open.

Bertucci’s said it had reached a tentative deal to sell its assets to Chicago-based Right Lane Dough Acquisitions LLC for nearly $20 million.

One of the locations closing is in Taunton, where in May 2016 a man with a knife fatally stabbed teacher George Heath as he came to the aid of a pregnant waitress. In his honor, Bertucci’s put a plaque on Heath’s favorite barstool. His widow, Rosemary, said that Bertucci’s has given her the stool.