Prior to the shooting, Fryberg invited several students, all of whom were friends, to meet him for lunch via text message. He also reportedly sent a text message to his parents, although details of the message have not been revealed. At lunchtime, the friends sat together at one table. Fryberg then entered the school cafeteria and sat down at a different table. At 10:39 a.m., according to eyewitnesses, he stood up, approached the table where the friends were sitting, and had a verbal altercation with them. He then pulled out a .40-caliber Beretta handgun and fired at least eight shots,shooting several students in a "calm, methodical way". During the shooting, Fryberg was described by a witness as having "a blank stare" and "staring at the victims as he shot them". He also appeared to be targeting only the table where his friends were sitting. At the time of the shooting, about ten students were seated at that table.
Fryberg died at the scene from a self-inflicted gunshot wound. An early eyewitness report stated that an adult school staff member tried to intervene by grabbing Fryberg's arm, inadvertently causing him to fatally shoot himself in the neck. The employee was later identified as first-year social studies teacher Megan Silberberger, who tried to apprehend Fryberg as he may have been attempting to reload. Police officials and the Snohomish County medical examiner later clarified that Fryberg committed suicide by shooting himself in the head and that Silberberger did not touch him in the moments preceding his death. Shortly after Fryberg committed suicide, Silberberger contacted authorities. The motive for the shooting is unknown, although a student at the school stated that "[he] was angry at a girl who would not date him, and that the girl was one of the people shot", a claim that was supported by other classmates and by Fryberg's family members.