Upper Crust Pizza has filed for bankruptcy. The company defaulted on a loan in September and owes at least $3.4 million, according to the Boston Globe.

The filing came after years of controversy for the local chain. Unfair labor charges and legal wrangling amongst owners dominated headlines over the past few years. 

The chain was repeatedly hot with unfair labor practice claims, from forced kickbacks to unpaid overtime. More recently, company co-owners have turned on each other, each claiming the other has used the company for personal gain.

Upper Crust operates locations in Beacon Hill, Back Bay, Brookline, Fenway, South End, State Street, West Roxbury and other spots across eastern Massachusetts.