One person has died after tourists became trapped in a 1,000-foot-deep gold mine in Colorado. What happened?

Authorities say one person died after an elevator malfunctioned at a former Colorado gold mine on Thursday, trapping more than a dozen visitors 1,000 feet underground for about seven hours.

The tour group was about halfway to the bottom of Mollie Kathleen’s gold mine in the town of Cripple Creek when an unspecified mechanical failure occurred just before noon during a trip that usually took two minutes. According to Mikesell, eleven tourists were quickly evacuated from the elevator, including two children, and four of them were treated for minor injuries. Meanwhile, another group of 12 people were stuck at the bottom

No further information was released about the person who died in the crash, and as of Friday morning, their name and cause of death had not been released.

At a news conference late Thursday afternoon, Teller County Sheriff Jason Mikesell said the 12 people stuck in the shaft had access to the water and were in contact with authorities on the ground via two-way radio before the elevator was reopened.

According to Mikesell, who said an investigation has been launched into the fatal incident, rescuers stand ready to pull trapped guests to the surface using ropes if they fail to restart the elevator.

Mikesell said the situation, which was successfully resolved on Thursday evening, created a “serious danger” to people stuck in the mine.

“I am relieved that the 12 people trapped in the Mollie Kathleen mine were safely rescued,” Colorado Gov. Jared Polis said in a statement after the ordeal. “We offer our deepest condolences to the family and friends of the person who died in this incident.”

This week was supposed to be the last week of the mine before the season closed. On Friday, the mine’s website informed visitors: “Mollie Kathleen recently experienced a tragic event. We would like to send our prayers and condolences to everyone involved. We would also like to thank all the rescue services and rescuers who helped us during this difficult time. Mollie Kathleen will be closed until further notice.”

Although the mine is no longer operational, it has been providing tours for “well over 50 years,” Mikesell said.

The Mollie Kathleen Gold Mine offers visitors the opportunity to “experience the ‘Old West’ as it was for hard-rock gold prospectors at the ‘World’s Largest Gold Camp.’ The one-hour tour costs $30 for adults and $18 for children. The “Need to Know” section of the attraction’s page is labeled “Claustrophobia” and states that “the tour itself is not claustrophobic, but the descent down the shaft is very close and takes 2 minutes (each way).” However, he adds encouragingly: “You can do it(!).”

According to the Colorado Division of Reclamation, Mining and Safety, all mines in the state that welcome tourists must be inspected daily for “adequate ventilation, ground conditions and controls, electrical hazards, general mine hazards, etc.”

In a social media post, the local fire department wrote: “We are thrilled to hear that all 12 people still inside the Mollie Kathleen Gold Mine were safely rescued. “We are grateful for the work of all the rescue services who ensured the safety of those inside. Our condolences to the family who lost a loved one this evening. Please remember them in your prayers.”