At least one person has died and 12 remain trapped in a disused Colorado gold mine after a lift malfunctioned, officials say.
The group were touring Mollie Kathleen Gold Mine in Cripple Creek – a privately-owned tourist attraction for more than 50 years.
Emergency workers have rescued 11 people, including two children, so far. At least four have minor injuries.
“There is an elevator issue to resolve before they could be brought up,” Teller County Sheriff Jason Mikesell told reporters on Thursday.
The hour-long tour takes visitors 1,000ft (305m) down the shaft into the south-west side of Pikes Peak, according to the tour company’s website.
Officials said the lift descending into the gold mine had a mechanical issue around 500ft beneath the surface, creating a “severe danger for the participants”.
“We did have one fatality that occurred during this issue at 500ft,” Sheriff Mikesell said. He did not give details.
Rescue teams are using radio to communicate with the 12 others who are stuck near the bottom of the mine.
“They have chairs, blankets, water and are at a safe temperature,” Sheriff Mikesell said. “This was due to an equipment malfunction. The mine did not collapse.”
Officials are hoping to fix the lift.
“But we also have a plan B and a Plan C already set in place with rescue officers in case of an issue,” Sheriff Mikesell said.
Several agencies, including search and rescue teams, are responding to the incident with heavy equipment.
Colorado Governor Jared Polis said state resources had been allocated to assist with the rescue efforts.
“We will do everything possible and assist the county to ensure a speedy and safe resolution of the situation,” Governor Polis said.
The fire chief of nearby city Colorado Springs said his firefighters were also helping with the rescue.
“My crews are specially trained to respond to incidents like this when called upon,” said Randy Royal.
According to the tour company’s website, entering the 1890s gold mine is comparable to riding in a lift, complete with the sounds of mining machinery.
The temperature at the bottom is 50F (20C) . There are no toilets underground and visitors are given hard hats.
Visitors to the Mollie Kathleen view several exposed gold veins in their natural state, the website says.
The website adds that revenue from the tours is used to “maintain the mine in safe operable mining condition”.
Officials said the last time an “incident” occurred there was in 1986, though they did not provide more detail.
On TripAdvisor, several people described the lift as a miners “cage”. The posts, which the BBC could not verify, said conditions could be tight and claustrophobic.
William Snare, a former hoist operator at the mine, told the Colorado Springs Gazette that the lift can carry between nine to 15 people. He said it takes two minutes to descend, and four to five minutes to return to the surface.
State Senator Mark Baisley, a Republican who represents Teller County, told CBS News that the “best outcome” is “a lot of families get together to recover from the fatality and to comfort each other”.
“But I’d sure like to see those 11 people – 12 people including the employee – be brought up tonight.”
The mine was named after Mollie Kathleen Gortner, the first woman in the Cripple Creek Gold Camp to strike gold in 1891.
The tours were set to close this Sunday for the season.