Eight police dogs die inside truck after the air conditioning unit breaks during 'freak accident'

Eight police dogs have died in the US after a truck's air conditioning unit broke down in the middle of a heatwave.

The German Shepherds were being transported from O’Hare Airport in Chicago to a K9 training facility in Michigan City, Indiana when the driver became stuck in a two-hour traffic jam.

During this, the air-conditioning unit that was being used to keep the dogs cool in the back of the truck stopped working.

As a result, the temperature inside the cargo area began to rise and some of the dogs went into heat-related medical distress.

The driver only realised there was something wrong when some of the dogs started barking.

He quickly pulled over after discovering the issue and attempted to help the dogs.

"The driver stopped the vehicle at the Road Ranger on Ripley Street and entered the cargo area. Once inside the the cargo area, he observed the canines in distress and began to remove the canines who were crated," the Lakeside Police Department said in a statement.

People then began to call the Lake Station Fire Department and EMS along with the Lake Station Police Department.

"There was an overwhelming response from both agencies so much so that civilians and so many others stopped to help where they could. The scene was chaotic and took an emotional toll on all that were involved in trying to save as many canines as possible," the statement read.

"Any loss of life is tragic and thoughts and prayers are with all those that were affect by this 'freak event'.

"The Lake Station Police Department believes after speaking with the person(s) involved that this was not an act of animal cruelty or neglect but a mechanical failure of the AC unit that was being used in the cargo area."

Images shared by the Humane Society of Hobart, Indiana show law enforcement and animal rescuers desperately trying to save the dogs in a gas station carpark.

“They were seizing on the scene, dying on the scene and had heatstroke,” Jenny Webber, the executive director of the Humane Society of Hobart, told NBC.

“This was really shocking for us."

Five dogs remain hospitalised in a nearby animal hospital.