(Willamina, OR) -- A Yamhill County Sheriff's deputy and students at Willamina Middle School are recovering after being overcome by fentanyl a student was apparently burning in a restroom. The deputy was asked to investigate a strong, acrid smell in the restroom in a modular classroom. The deputy started experiencing symptoms of an overdose and three students were also affected. One student was hospitalized along with the deputy. Investigators learned a student was apparently burning counterfeit pills with fentanyl on a piece of foil. The Willamina School District sent a notification to parents about the incident. The sheriff's office says there have been several fentanyl overdoses since the weekend, one of which was fatal. They're concerned a batch of counterfeit pills being distributed might be especially potent.