Police now know what caused a Greyhound bus to slam into a semi-truck on I-71 earlier this month. 32 passengers were on board the bus on 71 near Verona, when a tractor-trailor full of furniture pulled into traffic. Investigators say the semi didn't signal while it was trying to merge into traffic and was on the shoulder going only 25 miles an hour. Police say the bus driver tried to avoid hitting the truck at the last minute, but slammed right into it causing the front section of the bus to cave in. Police also say the bus driver was tired, and semi-truck driver was improperly parked on the side of the road. No one will be charged in the accident.