PHILADELPHIA — A hitchhiking robot that captured the hearts of fans worldwide has met its demise in the U.S.

The Canadian researchers who created hitchBOT as a social experiment told The Associated Press that someone in Philadelphia damaged the robot beyond repair early Saturday, ending its first American tour after about two weeks.

“Sadly, sadly it’s come to an end,” said Frauke Zeller, one of the robot’s co-creators.

The kid-size robot set out to travel cross-country after successfully hitchhiking across Canada in 26 days last year and parts of Europe. It’s immobile on its own, relying on the kindness of strangers. Those who picked it up often passed it to other travelers or left it where others might notice it.

It started in Marblehead, Massachusetts, on July 17 with its thumb raised skyward, a grin on its digital face and tape wrapped around its cylindrical head that read “San Francisco or bust.” The robot bounced around the Boston area and was briefly taken to sea, but never made it off the East Coast.

The creators were sent an image of the vandalized robot Saturday. They said they don’t know who destroyed it or why.

According to CBC News in Canada, the last people who picked up hitchBOT were YouTube star Jesse Wellens, whose channel featuring prank videos has more than 8 million subscribers, and his buddy Ed Bassmaster. The bot was last seen near Elfreth’s Alley and 2nd Street in Philadelphia, where the duo dropped it off, according to hitchBOT’s live map.

Some of the robot’s followers went to the area to retrieve the remains after the incident, and its “brain” containing the software is still intact, David Smith, a McMaster University professor and co-creator of hitchBOT, told CBC News. His team is now arranging for the parts to be shipped back to Canada to determine the next step of the experiment.

Zeller said her team doesn’t plan to release the last photo of hitchBOT to protect young fans who might be distraught.

“I hope that people won’t be too disappointed, too sad,” she said.