An experimental hitchhiking robot that relied on the kindness of strangers to get around has been found damaged beyond repair in Philadelphia. HitchBOT was only two weeks into an attempt to cross the United States and had already successfully travelled through Canada, the Netherlands and Germany without incident.

The child-sized machine was created as part of a social experiment in human attitudes towards robots. Described as an “art project combined with science and technology” by Dr. Frauke Zeller, one of the robot’s creators, hitchBOT was immobile on its own and entirely dependent on strangers to pick it up and pass it on to other travelers.

HitchBOT had access to a range of trivia within its memory, and its speech recognition software allowed for limited conversations with travelling companions. The robot could even ask a driver to plug it into an outlet or cigarette lighter if its battery was running low. A GPS was also placed in hitchBOT to track its location, and a camera took photos about every 20 minutes to document its travels.

HitchBOT’s US tour had started in Marblehead, Massachusetts, on July 17. It traveled around Boston, where it checked off one of the items on its bucket list by attending a Red Sox baseball game. The robot’s adventure came to a premature end upon reaching Philadelphia on Saturday, when someone beheaded hitchBOT and removed all its electronics.

The creators were sent an image of the vandalized robot but cannot track its location because the battery is dead. They said they don't know who destroyed it or why. Zeller added that she is most concerned about the children who loved it and followed its journey on social media.

"We have no interest in pressing charges or finding the people who vandalized hitchBOT; we wish to remember the good times, and we encourage hitchBOT's friends and fans to do the same," the robot's creators wrote in an update.