LITTLE CANADA, Minn. (AP) — Pigs ran loose on a metro highway after a semitrailer truck that was carrying 50 hogs overturned, causing 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, the Star Tribune reported.

The truck tipped over around 7:35 a.m. and caused morning rush hour traffic to back up for more than a mile, Minnesota Department of Transportation cameras showed.

The truck driver was not hurt, according to Lt. Gordon Shank with the Minnesota State Patrol. Ten pigs died in the crash.

Authorities rounded up the pigs, some of which were injured.

Investigators are looking into what caused the semi to tip on its side as it navigated the curve on I-694 where it joins with northbound Interstate 35E.

Nearly five years ago, more than 20 pigs spilled onto the roads in a more rural part of the state after a semitruck overturned at a highway interchange near Mankato. About 90 pigs had been in the livestock trailer, and some of them died. The driver suffered minor injuries.

And last year on a Pennsylvania highway, several monkeys escaped when a truck that was towing a trailer of 100 monkeys collided with a dump truck. The truck had been on its way to a lab. The drivers weren’t harmed.