Three persons were killed and 50 others injured when a passenger bus fell into a gorge in Madhya Pradesh's Chhindwara district, police said on Tuesday.The private bus, plying on the Chhindwara-Narsinghpur road, met with the accident on Monday night, according to the police control room. The injured said the bus was packed beyond its capacity.Chief Minister Kamal Nath visited the injured in the district hospital on Tuesday.