Several people sought medical help after suffering eye irritation and skin burns at the Frank Cochran Center this weekend.
A mercury vapor bulb apparently leaked during Friday night's Toughman Competition.
Parks and Recreation Director Mark Naylor said the city was notified Saturday and corrected the problem. He said it's not known how the bulb was damaged.
Naylor said an emergency room doctor told him the bulb emits ultraviolet light, like the sun. Some of those attending the event went to emergency rooms for treatment.