Des Moines, Iowa —A malfunctioning ventilation system prompted the temporary evacuation of Wells Fargo Arena Monday evening, during halftime of the Class 3A quarterfinal between Estherville Lincoln Central and Cherokee in the Iowa girls state basketball tournament.

At around 7:30 p.m., Monday, the Iowa Girls High School Athletic Union posted on social media that spectators in the arena were being asked to evacuate the building while officials determined the cause of the alarm.

In a follow-up post a few moments later, the IGHSAU said it was determined that the alarm was triggered by a malfunctioning ventilation system in a concession stand and fans were allowed to return to the arena.