The police stated that 21-year-old was found dead in his apartment from an apparently inflicted gunshot wound and the suicide note found next to him.
Former Washington State linebackers coach Roy Manning, who recently left for a position at UCLA, tweeted, "Words can't describe what I'm feeling right now".
Cougars head coach Mike Leach released a statement about Hilinski's passing: "We are deeply saddened to hear the news of Tyler's passing".
Hilinski, a redshirt sophomore, took over for Luke Falk in the Holiday Bowl after the starting senior quarterback injured his wrist.
The campus of Washington State University in shock and mourning because of the suicide of the football player Tyler Hilinski's death. He threw for 1,176 yards seven touchdowns.
Hilinski's teammates were informed of his death Tuesday evening and were offered counseling, Johnson said in a statement.
On the football field, WSU fans may best remember Hilinski leading the Cougars to a triple-overtime comeback win against Boise State. "There, they were met by campus and department counseling and psychological services, including athletics" on-staff clinical psychologist and a licensed mental health counselor, along with WSU Athletics medical team.
Hilinski is but one tragic story made a national story by his high-profile position as a scholarship athlete. Those who have suicidal thoughts must know that there are people out there who love them and are willing to help them in times of despair.
The WSU community is mourning the loss of student and Cougar quarterback Tyler Hilinski.