At 04:03 hours units were alerted to the 137.5 I95 Southbound for the Auto Accident with Entrapment. As units were responding, Communications informed units of a overturned coach bus. Engine 2 arrived on the scene to confirm dispatch information with multiple people trapped. The Operations Deputy Chief then requested the incident be upgraded to a Mass Casualty Incident and requested an additional Rescue Company. Units were able to gain access to the patients by removing the front windshield. Rescue 1 arrived on the scene moments later and assisted with gaining access to the patients. While this was happening, Rescue 1's Driver prepared to remove a section of the roof but was informed that units had ample amounts of access. Rescue 1's crew assisted with triaging patients and also assisted Virginia State Police before returning to service. Units operated for approximately 3 hours.