Federal authorities are investigating a rockslide that killed a worker at a Sterling quarry on Thursday, and the Worcester County town’s Select Board has sent a cease-and-desist notice to the company that operates the quarry.

Sterling Police dispatch received a call about the rockslide around 8 a.m., Police Chief Sean Gaudette said during an emergency Select Board meeting Thursday afternoon. Upon arrival, officers and firefighters found that “a large piece of rock face had slipped and fallen onto an excavator,” he added.

“At that point, firefighters were conducting rescue operations … but they could not find any signs of life,” Gaudette said.

“Emergency responders used camera equipment to investigate the collapse site,” the Worcester County District Attorney’s Office said in a statement.

At 8:39 a.m., rescue workers declared the worker dead, the office added. Emergency crews continued to work to recover the deceased into the afternoon.

Authorities have not disclosed the worker’s identity.

“Please avoid the area. There is no safety threat to the public,” the Sterling Fire Department said in a social media post this morning.

Sterling, a rural town of about 8,000 residents, is located about 40 miles west of Boston.

Demolition and excavation company Onyx Corporation operates the quarry on Chocksett Road, off Route 12 and near Interstate 190. The company announced online that it has closed all locations from Thursday through the weekend and will resume operations on Monday.

This happened before the Select Board’s emergency meeting.

“Our thoughts are with those affected at this time,” said chairwoman Kirsten Newman. “As the earthmoving approval authority, I believe it is important that we discuss this approval now.”

“I would like to suggest that we issue a cease and desist order for the time being until we receive a full investigation from the authorities,” she added. “I would also like to thank our local first responders who went into an unknown situation and risked their lives to try to rescue the trapped worker.”

A man reached at a business number associated with the quarry said: “I don’t have anything at the moment.”

In February 2018, Onyx announced the location of its Sterling Quarry.

“Whether you are a small landscaper or a large construction contractor, we have the locations and expertise to supply you with whatever sand or aggregates you need,” the company posted online at the time.

The company announced in January that it converts boulders into aggregates used for roads, drainage, retaining walls and other infrastructure.

In response to the rockfall, federal authorities as well as numerous local and state agencies were called to the quarry.