Pigs ran loose on a metro highway after a semitrailer truck that was carrying them overturned. It caused an hours-long shutdown Friday morning in Minnesota on Interstate 694. State troopers tried to corral several loose pigs that cameras showed running through traffic. Department of Transportation cameras showed the truck tipping over around 7:35 a.m. and causing morning rush hour traffic to back up for more than a mile. The Minnesota State Patrol says the truck driver was not hurt. Authorities rounded up the pigs, some of which were injured. Investigators are trying to figure out what caused the semi to tip over.