Six youths were killed when the car they were travelling in fell into a dam in Sehore district of Madhya Pradesh, police said on Monday.The incident took place on Sunday when the driver of the speeding car lost control over it. The youths were on their way to Kolar from Bhopal for a picnic.The car could be taken out only on Monday after the water level in the dam subsided, Sehore Superintendent of Police Rajesh Chandel said.