In national news tonight:Alcohol may have been a factor in a fatal boat accident this weekend in Detroit, Michigan.Three people are dead and another person remains seriously injured.The 21 foot boat was speeding when it slammed into a dock.The accident instantly crushed the boat.The boat owner and another couple were killed.The boat owner's wife was airlifted to the hospital.Witnesses describe the scene as pure panic.GUC says: "The boat was so mangled it took probably 20 minutes or so just to get them out. The boat was all crushed up and we were trying to hold the people in place while they took the boat apart to get them out. So, that was a pretty rough thing to see."Police say they found open and closed containers of alcohol on board the boat.The investigation continues for the cause of the crash.