Town of Sterling orders work stoppage after ledge at rock quarry collapses on excavator operator - MASHAHER

The town of Sterling issued a work stoppage after a ledge at a rock quarry collapsed on an excavator operator on Thursday morning, prompting a large emergency response, officials said.

Rocks fell on the operator at an Onyx Corporation industrial site near Chocksett Road just after 8 a.m., according to the Sterling Fire Department.

There was no word on the condition of the worker who was left trapped in the rubble.

In a post on Facebook, the department said firefighters and other emergency agencies were working at the “active” scene.

While there is no safety threat, the public was urged to avoid the area until further notice.

“It was a wall or a piece of the ledge or something that fell off the side of the hill and hit the machine the man was driving. That’s all I know,” said Terry Heinold, a former owner of the quarry. “Something went wrong and he’s trapped.”

Heinold noted rescue crews from multiple towns were called to the scene, calling the incident “unfortunate.”

Onyx Corporation operates a demolition and excavation company, providing sand, gravel, and other aggregate needs.

After the ledge collapsed, the Sterling Select Board held an emergency meeting and sent a cease-and-desist order to Onyx, calling on them to suspend earth removal until after an investigation is conducted at the site, Town Administrator William Caldwell confirmed in a statement.

In a Facebook post, Onyx announced the closure of their locations in Acton, Leominster, Westford, and Sterling through the weekend. It will resume business on Monday.

Onyx declined to comment on the incident when contacted by Boston 25 News.

Boston 25 News photographer Ken Lucas flew a drone over the quarry, capturing video of a large pile of boulders and multiple excavators roped off with yellow tape.