At 9:54 am Sunday, the East Contra Costa Fire Protection District was dispatched to a report of a motorcycle crash at Diablo MX Ranch.
It was reported that a subject approximately 50-year-old lost consciousness and then had a seizure. The male then became combative.
Engine 53 arrived on scene with the ride up on his feet, however, still requested a medical helicopter due to the head injury.
By 10:16 am, CALSTAR landed at the scene.
No further information was available.