A flammable ink product was found leaking from a truck trailer Monday evening on Interstate 41 just south of Fond du Lac, according to city of Fond du Lac Fire/Rescue. Law enforcement noticed a semi truck trailer leaking a liquid from underneath the cargo doors as the semi was traveling around 8:30 p.m. Monday southbound on Interstate 41. They stopped the truck just south of Highway 151 and called a hazardous materials team from Fond du Lac Fire/Rescue. First responders found the source of the leak was a punctured 55-gallon drum inside the truck trailer that had contained flammable ink. All the ink had leaked out, streaming from the drum into the back of the trailer and onto the highway.