CANBERRA, Australia (AP) — Two workmen used a backhoe to dig up grass, topsoil and 10 palm trees from an Australian front yard before realizing they were at the wrong address and fleeing, a homeowner said Thursday.

Peter Collard, 56, said the culprits did an estimated 20,000 Australian ($18,000) in damage in front of a six-bedroom house he was trying to sell in the eastern city of Brisbane — and that his insurer told him none of the damage was covered by his policy.

Collard's real estate agent saw the men Wednesday during an inspection and was told they had instructions to clear every tree. The agent called Collard to confirm.

"I rushed home and couldn't believe what I saw — the sheer devastation was unbelievable," Collard said. "The two guys just took off. They just left all the trees where they'd bowled them over," he added.

Collard, who was asking AU$665,000 for the house, said he suspected the men had instructions to excavate a yard for a swimming pool.

After Collard arrived and challenged the men, they hastily loaded their backhoe onto a dump truck and fled without explanation, Queensland state police spokeswoman Susan Grantham said.

"They just picked everything up and were gone," Grantham said.

Collard appealed to any homeowner who had excavation work planned in his upscale suburb of Mackenzie to contact police to help identify the culprits.