One person is dead and 12 are trapped in a former Colorado gold mine after an elevator malfunctioned at the tourist site, authorities said Thursday.

The elevator descending into the Mollie Kathleen Gold Mine near the town of Cripple Creek had a mechanical problem around 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 news conference.

Twelve people are still at the bottom of the mine, which is about 305 metres beneath the surface. They are in safe conditions and in communication with authorities, said Mikesell.

Rescuers are working to get the elevator working. Mikesell declined to identify the victim or say how they died.

The sheriff said they could rescue the trapped group by rope if necessary, but were hoping to get the elevator system working.

Mikesell said the last time there was an incident was 1986. Gov. Jared Polis said in a statement that the state was sending resources for the rescue effort.

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

The mine opened in the 1800s and was closed in the 1960s but still operates tours. The mine’s website describes a one-hour tour in which visitors descend 100 storeys into the earth. It says visitors can see veins of gold in the rock and ride an underground tram.

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