Matthew Truax was 16 and a junior at the school.
The Snohomish County Medical Examiner said a condition called "hypertrophic cardiomyopathy" caused his death. It is described by medical experts as a condition in which the heart muscle becomes thick without any obvious signs. The thickening prevents it from pumping effectively and can cause sudden cardiac arrest.
Meadowdale staff called 911 just before 10 a.m. Friday, according to school and fire officials.
Teachers began CPR, and firefighters took over. The boy was unresponsive when crews arrived. He was taken to Swedish/Edmonds hospital.
More Local News Headlines
With low recidivism, mental health court shows progress County Council sets hearing on Paine Field museums proposal Mukilteo School District puts 6-year capital levy on ballot Glacier Peak arson probe continues after 9 months Police, parks in Lake Stevensí 2016 budget Volunteers at Edmonds church assemble meal to be thankful for Fire closes Everett toy store; no one hurt New administrator, new energy for Oak Harbor seniors
Our new comment system is not supported in IE 7. Please upgrade your browser here.