Students at Golden Valley High School in Merced came in on their day off to be a part of a mock lockdown.
On Saturday, students, teachers, parents, emergency services, Merced police officers and Merced fire fighters gathered at the school to participate in the drill.
It was done to test out how to respond if anyone ever shot a gun inside the school.
School officials estimated that over 100 people participated in the drill.
This is the first time the district has done this type of training.