Six people died on the spot and another 20 were injured in an accident early on Sunday on the Agra-Lucknow Expressway in Kannauj district. Most of the passengers were migrant workers from Bihar returning to their work places in Delhi.Police said a passenger bus coming from Madhubani in Bihar rammed into a stationary SUV on the side of the road near Saurikh. Both the vehicles fell 20 feet below.Four persons died on the spot, two on the way to the hospital. The injured were shifted to Saifai and Tirwa hospitals, the police said.Police said the SUV driver headed for Ludhiana, had stopped to take a nap, on the road-side. The speeding bus rammed into the car with such a force that both came rolling down 20 feet.The Expressway guards and the police reached the accident site within minutes to rescue the survivors.