Seizure in car while driving to a seminar: Covered by workers’ comp?

Q. We are a small business with 20 employees. We sent a crew of maintenance men (hourly employees) to seminar about two hours away. On the way, one of the guys had a seizure in the car and was taken to the hospital via ambulance. Diagnosis was low electrolytes. Apparently, after speaking to the employee, he has had this before but never followed up with a doctor. We were unaware of these problems and he has been with us for about three years. My question: Because he was technically on the clock on the way to the seminar, is this workers’ compensation? Personal insurance? All he was doing was riding in the vehicle? No strenuous activity. -- N., New York