Stephen Colbert and cellist Yo-Yo Ma were rushed out of a Harvard University event Thursday after a fire alarm was pulled during their appearance, which had drawn hundreds of union protesters outside who objected to the pair crossing their picket line. The Harvard Graduate Student Union had urged both performers to cancel the talk in solidarity with their strike, which began October 27. Despite the protests and chanting outside the venue that made it difficult to hear the speakers, Colbert and Ma proceeded with the event.

The fire alarm forced organizers to end the event during the question-and-answer portion and escort Colbert out of the building. The union denied responsibility for the alarm, stating in a social media post that it was unrelated to their picketing activity and that members were relieved no one inside was at risk.

The union had sent multiple formal communications to Colbert and Ma's teams in advance, requesting they move the event off-site or virtually, reschedule, or cancel to avoid crossing the picket line. Representatives from Colbert's union, SAG-AFTRA, and Ma's union, the Boston Musicians Association, also reached out on the graduate union's behalf with the same request. The union said Colbert and Ma refused to speak with union members as they left and continued the event without regard for the picket line.

The graduate student union has been on strike demanding a contract that includes wage increases and protections for non-citizens and against harassment and discrimination. Graduate classes have gone untaught since the strike began. Author John Green moved his own Harvard event to accommodate the strike, calling it an easy decision and donating his proceeds to the union.