A chemical spill at Skyview High School in Vancouver, Wash., Thursday morning sent two adults and seven students to a hospital as a precaution for trouble breathing.
Schools spokeswoman Pat Mattison said a fire department hazmat crew cleaned up a mixture of bleach and ammonia in a classroom.
Mattison told The Columbian a student brought the mixture and was showing it to another student when it spilled on the floor. Mixing bleach and ammonia can produce toxic fumes.
The Clark County sheriff's office is investigating.