An e-cigarette is reportedly to blame for a small explosion at Sparks High School gym in Nevada.

Washoe County (Nev.) School District police blame an electronic cigarette for a small explosion at the Sparks High School gym on Monday that prompted a code yellow lockdown and a partial evacuation.

School officials called police at about 10:15 a.m. after they received a report of a fire in the gym, Principal Kevin Carroll said.