ROBY, Texas (AP) — A broken mercury vapor light bulb in a gymnasium has been blamed for making more than 100 people sick after high school basketball games in West Texas.

The Roby (ROH'-bee) Consolidated Independent School District on Monday reported results of an investigation following the Jan. 6 games with Trent. Dozens of people who attended later reported having sore throats, headaches and irritated eyes.

Superintendent Heath Dickson says investigators originally thought cleaning chemical residue on metal bleachers was responsible.

Dickson says staffers in the gymnasium on Jan. 13 noticed a strange smell after the lights were on for an extended period. Officials located a cracked bulb.

Tests determined the emission of ultraviolet radiation.

The remaining similar light bulbs have been replaced.