WEST LAFAYETTE, Ind. (AP) — The Office of the Indiana State Chemist is investigating after a crop duster accidentally dropped a pesticide on more than two dozen corn detasselers two weeks ago in Williamsport.

Robert Brewer, an investigator with the office, is interviewing people involved with the incident and testing soil samples for pesticide residue. He told the (Lafayette) Journal & Courier he’s awaiting lab results and isn’t sure yet whether Bi-State Helicopters was responsible for any violations.

About 25 corn detasselers were struck by a drift of the fungicide Quilt Xcel while working near a field where it was being applied. The workers were taken to a local hospital for treatment. The July 15 incident also is being investigated by the Federal Aviation Administration and the Indiana Occupational Safety and Health Administration.