Police say they found ammunition and homemade explosives in the locker of a western New York high school senior after he used a sawed-off shotgun to commit suicide in a bathroom.

Police raced to Canandaigua Academy on Tuesday morning while students were being told to remain in class. They later evacuated the school in Canandaigua, a city of 11,000 residents just southeast of Rochester. The students were taken to a nearby middle school.

Police Chief Jonathan Welch said 17-year-old Thomas Kane died of a self-inflicted gunshot wound. An investigation will determine if other students were involved.

A search of Kane's locker revealed 30 rounds of ammunition and two Molotov cocktail-type devices made of bottles filled with liquid and corked with rags, police said.