Chipotle’s Augusta, Maine, location, which recently became the fast casual’s first store to file for a union, officially closed Tuesday due to understaffing, according to the company. 

The moves comes less than a month after employees filed to be recognized as independent union Chipotle United. The workers, who walked out of their shifts in protest beforehand, were seeking safe, adequate staffing at the store. The group sent a letter to Chipotle alleging two people were expected to handle the workload of six and that three to four people opened the restaurant when at least seven should be present. 

Brandi McNease, an employee at the location, described the closure as “union busting 101.” On Tuesday, the National Labor Relations Board was scheduled to hold a hearing on the store’s union election process, Maine ALF-CIO representative Andy O’Brien told the Bangor Daily News. Chipotle United reportedly filed an unfair labor practice complaint against the company. 

“There is nothing that motivates us to fight harder than this underhanded attempt to shut down the labor movement within their stores. They’re scared because they know how powerful we are and if we catch fire like the unionization effort at Starbucks they won’t be able to stop us,” McNease, said in a statement.

Laurie Schalow, Chipotle’s chief corporate affairs officer, said the unit has been closed to customers since June 17, but kept open for training to continue paying employees. The executive added that even though the company dedicated two recruiting experts to the single restaurant, the location kept suffering from call outs and lack of availability from existing staff. Finding managers was even harder, Schalow said. Workers will be paid for scheduled shifts through the rest of this week and four weeks severance. 

“Because of these ongoing staffing challenges, there is no probability of reopening in the foreseeable future, so we’ve made the decision to permanently close the restaurant,” Schalow said in a statement. “The employees at our Augusta restaurant will receive severance pay and outplacement assistance.”

Earlier in July, a second Chipotle restaurant in Delta Township, Michigan, filed to unionize, with assistance from the Teamsters Union. 

Meanwhile, Starbuck’s unionization continues to take hold across the country. More than 170 locations have voted to do so.