Police say witnesses saw him weaving in and out of traffic. 27 year old Kyle Lafferty of Walton has been killed in an accident Thursday night on I75 in Florence. The car Lafferty was driving slammed into a broken down semi that was parked on the right shoulder. The driver of the tractor trailer told police he had a mechanical issue with one of the tires and had stopped to make repairs. The cause of the accident remains under investigation.