Multiple ambulances and a Lifeflight helicopter were dispatched to the high school.
Worried parents rushed to the school in the town of about 500 people near the Idaho border, about 25 miles southeast of Spokane. The two-lane road into town was clogged as people sped to the school.
Cheryl Moser said her son, a freshman at Freeman High School, called her from a classroom after hearing shots fired.
"He called me and said, 'Mom there are gunshots.' He sounded so scared. I've never heard him like that," Moser told the newspaper. "You never think about something happening like this at a small school."
(With inputs from AP.)
A shooter opened fire at a high school in Washington state Wednesday, killing one person and injuring at least three others, authorities said.
Spokane County Sheriff Ozzie Knezovich said at the scene that the shooter was in custody, The Spokesman-Review newspaper reported.
Spokane Public Schools said on Twitter that all schools in the district are "being placed into modified lockdown as a precautionary measure."