Most people understand the Golden Rule of interacting with art and artifacts in museums: You can look, but you can't touch. Every now and then, however, precious relics are damaged when museum patrons ignore that convention in favor of getting handsy with exhibits. The latest item to fall victim to such a fate is an 800-year-old coffin at a museum in Essex, England, as Mattha Busby reports for the Guardian. The artifact was broken when visitors tried to stage a photo-op by placing a child inside the coffin.

The incident occurred earlier this month at Southend's Prittlewell Priory Museum, which is home to a centuries-old coffin that may have held the body of a high-ranking monk, according to the local Echo newspaper, which first reported the story.

The BBC reports that the culpable visitors lifted a child over a set of plastic barriers and into the artifact. Without trying to unpack the psychologically perplexing impulse to lower a little kid into a coffin, needless to say, it was a very bad idea, and because of it, the sarcophagus tumbled over. In the process, a piece of the artifact broke off.

The visitors left the museum without reporting the damage, but their actions were captured on CCTV footage.

“The care of our collections is of paramount importance to us and this isolated incident has been upsetting for the museums service, whose staff strive to protect Southend’s heritage within our historic sites,” says Claire Reed, the conservator tasked with repairing the sarcophagus, according to Busby.

“My priority is to carefully carry out the treatment needed to restore this significant artefact so it can continue to be part of the fascinating story of Prittlewell Priory.”

The museum is based in a medieval priory founded by the Cluniac order of monks in the 13th century. In 1921, the sandstone coffin was discovered on the grounds of the property, with a skeleton inside.

It is not the first time this summer that photo-takers have inadvertently wreaked havoc at museum exhibitions. Back in July, a woman toppled a row of fragile pieces by the British artist Simon Birch while trying to take a selfie at a pop-up gallery in Los Angeles. She caused approximately $200,000 in damages.

Fortunately, conservators at the Prittlewell Priory will be able to restore the broken coffin for a much more palatable sum. According to Busby, repairs are expected to cost less than £100 (about $128 USD). But the local council is nevertheless planning to keep the coffin "completely enclosed" from hereon out.