A Utah cemetery association was not negligent over the death of a four-year-old boy who was crushed by a historic headstone, a jury found.

Jurors delivered their decision in a family lawsuit over the death of Carson Dean Cheney, who was hiding behind the 250lb tombstone that fell while he took photos with his family in Park City.

Lawyers for the boy's parents say the Glenwood Cemetery Association's shoddy maintenance left the headstone weak and that it failed to warn people about potential danger even though headstones had fallen before.

The association says its volunteers conducted frequent inspections of the cemetery and the headstone was solid until the boy started playing on it on July 5, 2012.

Association lawyer Paul Belnap said that while the group was sorry for the boy's death, they appreciated the jury's work in the case.

The Cheney family was disappointed with the decision in lawsuit they saw as a way to help make ageing cemeteries safer, said family lawyer Ron Kramer.

The cemetery opened in 1885 for silver miners and their families, but as the industry faded, it fell into disrepair.

The association restored the cemetery and welcomed the public, including school groups that did rubbings on gravestones, Mr Kramer said.