George was a passenger on a Bluedog bus.The bus had been chartered by a local restaurant to take its good customers to a Rangers game in Arlington.As the bus was going down Interstate 20, the bus driver was trying to dislodge a stuck CD from his personal CD player.While he was thus occupied and not paying close attention, he ran over a landscaping timber that had fallen from another truck.There was a loud thump and a jarring bump when the bus hit the timber. The driver started to pull off the road to see what happened, but the passengers, anxious to get to the game, hollered at him to keep on driving. He hollered back "OK, but if this bus has a flat and rolls over because of that timber, it'll be on your heads!"They all just shouted louder to keep driving. Unknown to the driver, the timber had hit an exposed valve in the brake line, opening the valve, and letting the brake fluid escape.Later models of this bus had a protective panel over this valve, but this was an old bus, and did not have the protective panel.Several miles down the road the bus encountered the never-ending construction being done on I-20.The driver put on the brakes to slow down.... and they didn't work.The bus plowed into a huge mud bog, turning over, injuring many of the passengers.George was seriously injured in the accident, and died a few weeks later from complications of a surgery to set bone in his leg broken in the accident.Who can sue who for what, and what defenses might be raised by those sued?