A tractor-trailer hauling pigs overturned Tuesday on westbound Interstate 40 near downtown Raleigh, officials said.
The wreck happened about 10 a.m. between South Saunders Street and Lake Wheeler Road on a rainy morning rife with accidents around the Triangle.
Traffic on I-40 backed up as police and firefighters blocked two lanes. Passage through the area still was slow at 2:30 p.m., according to NC Department of Transportation maps.
There was no immediate report of injuries to the truck driver or others. The condition of the animals was not immediately known, though officials on the scene later said only about 15 percent of pigs survived.