Chipotle has permanently closed a restaurant in Augusta, ME, whose workers filed a petition to join a union last month. The chain said that the decision to close was based on an inability to run the restaurant due to “excessive call-outs and lack of availability from existing staff.” Chipotle United, which seeks to represent the restaurant’s workers, said the company was engaging in “union busting 101” and trying to discourage employees at other locations from seeking to form a union.