An occurrence which includes one or more of the following: a fatality at the time of the event (other than a suicide) or within 30 days of the event; injuries requiring immediate medical attention away from the scene for two or more persons; property damage equal to or exceeding $25,000; an evacuation due to life safety reasons; a collision at a grade crossing; a mainline derailment; or a collision between a rail transit vehicle and another rail transit vehicle or a transit non-revenue vehicle resulting in injuries that require immediate medical attention away from the scene for one or more persons.