At least eight dogs being transported to a K-9 training facility in Indiana died of heat-related illness on Thursday after the “mechanical failure” of an air-conditioning unit, authorities said. The Lake Station Police Department said in a Facebook post that the truck transporting the dogs from Chicago O’Hare International Airport to Michigan City, Indiana was caught in a two-hour traffic delay. The air conditioner in the cargo area, separate from the driver’s cab, broke down, causing the interior’s temperature to rise. “The driver’s attention as to what was going on inside the cargo area was alerted to him by some of the canines barking,” police said. The driver stopped at a gas station in Lake Station, where he began removing the dogs from their crates. Emergency 911 calls to the Lake Station Fire Department and police department prompted “an overwhelming response,” police said. “The scene was [chaotic] and took an emotional toll on all that were involved in trying to save as many canines as possible,” the department statement continued. “Any loss of life is tragic and thoughts and prayers are with all those that were [affected] by this ‘freak event.’”