One person was killed and officials were working to rescue 12 others trapped deep beneath the surface of a former Colorado gold mine after an elevator malfunctioned at the tourist site, authorities said.

The elevator descending into the Mollie Kathleen Gold Mine near the town of Cripple Creek had a mechanical problem around 500 feet (152 metres) beneath the surface, creating a “severe danger for the participants” and one person was killed, Teller County Sheriff Jason Mikesell said at a press conference.

Twelve people were still at the bottom of the mine, about 1,000 feet (305 metres) beneath the surface. They were safe and in communication with authorities, said Mr Mikesell. Rescuers were working to get the elevator back online.

The elevator accident was reported to authorities at about noon, the sheriff said. He declined to identify the victim or say how they died.

Two children were involved but it was unclear if they were among those who were trapped.

Colorado Gold Mine People Trapped
A police officer moves a barrier for an emergency vehicle (Arthur H Trickett-Wile/The Gazette via AP)

Eleven people who were riding the elevator were rescued, Mr Mikesell said. Four had minor injuries. The sheriff did not elaborate on how they were injured or the nature of the elevator’s mechanical problems.

The sheriff said authorities could rescue the trapped group by rope if necessary, but were hoping to get the elevator system safely working and to resolve the situation on Thursday night.

“We want to inspect it, make sure it’s safe before bringing them back up with it,” Mr Mikesell said. “We do have a plan B and a plan C already set in place with rescue officers.”

The state was sending an elevator expert to the scene.

Authorities were communicating with the trapped group with radios, but the group had not been told the extent of the problem with the elevator, according to Mr Mikesell, who added: “That’s because I want to keep people calm.”

The group had access to water and the atmosphere was considered good.

Among those trapped was a member of the family mining operation who has mine rescue experience.

Responders were trying to assess if the damage done to the elevator could lead to another failure before they send it back down. The elevator ride typically takes about two minutes, travelling about 500 feet (152 metres) per minute, according to the mine’s website.

Mr Mikesell said the last time there was an incident was in the 1980s but did not say what had happened.

Mines operated as tourist attractions in Colorado must designate someone to inspect the mines and the transportation systems daily, according to the state Division of Reclamation, Mining and Safety.

Mr Mikesell said he did not know the date of the last inspection. Records of the inspections were not immediately available online.

Governor Jared Polis said the state was sending resources, including a mine rescue team.

“We will do everything possible and assist the county to ensure a speedy and safe resolution of the situation,” Mr Polis said in a statement.

Cripple Creek is a town of about 1,100 people located in the Rocky Mountains southwest of Colorado Springs.

The mine opened in the 1800s and closed in 1961, but still operates tours. Its website describes a one-hour tour in which visitors descend 1,000 feet into the earth. It says they can see veins of gold in the rock and ride an underground tram.

A woman named Mollie Kathleen Gortner discovered the site of the mine in 1891 when she saw quartz laced with gold, according to the company’s website.