A tour guide died after visitors were trapped in a 1,000-foot-deep Colorado gold mine. What happened?

A tour guide was identified on Friday as the person killed when an elevator malfunctioned at a former Colorado gold mine, trapping a dozen visitors 1,000 feet underground for about seven hours, according to authorities.

The group of tourists were roughly halfway to the bottom of the Mollie Kathleen Gold Mine in the town of Cripple Creek when the unspecified mechanical glitch occurred shortly before noon on Thursday, amid what is normally a two-minute journey.

Ten tourists, including two children, were quickly rescued from the elevator, with four receiving treatment for minor injuries, according to Teller County Sheriff Jason Mikesell. An 11th person in the elevator, identifed on Friday as tour guide Patrick Weier, 46, was killed. The aspiring volunteer firefighter leaves behind a 7-year-old child, Cripple Creek Mayor Annie Durham said at a news conference.

After the elevator malfunctioned, a separate group of 12 — who were waiting at the bottom with another tour guide —remained stuck inside the mine for several hours.

On Thursday afternoon, Mikesell said the 12 people stranded in the shaft had access to water and kept in contact with authorities above ground via a two-way radio before the elevator was restarted.

An investigation has been launched into the deadly incident, according to Mikesell, who said rescuers were ready to hoist the trapped guests to the surface using ropes, if they couldn’t get the elevator running again. The cause is believed to have been a mechnical issue involving a door malfunction, which is now being probed, officials said Friday.

The situation, which was sucessfully brought to a close on Thursday night, created a “severe danger” for those stuck in the mine, Mikesell said.

“I am relieved that 12 of the people trapped in the Mollie Kathleen Mine have been safely rescued,” Colorado Governor Jared Polis said in a statement following the ordeal. “Our deepest condolences to the family and friends of the individual lost in this incident.”

This week was to be the mine’s last before closing for the season. On Friday, the mine’s website informed visitors: “Recently the Mollie Kathleen experienced a tragic event. We would like to send our prayers and condolences to everyone involved. We would also like to thank all of the first responders and emergency personnel who helped us through such a difficult time. The Mollie Kathleen will be closed until further notice.”

While the mine is no longer operational, it has been providing tours for “well over 50 years,” Mikesell said. On Friday, he described the family that runs the mine as a tourist attraction as “good people,” and said the incident was “just a very tragic event that occurred.”

The Mollie Kathleen Gold Mine offers visitors an oppotunity to “Experience the ‘Old West’ as it was for hard rock gold miners of ‘The World’s Greatest Gold Camp.’” The one-hour tour costs $30 for adults and $18 for kids. A section on the attraction’s “Need to Know” page is labeled “Claustrophobia,” and notes that the “tour itself is not claustrophobic but the descent in the shaft is very close for 2 minutes (each way).” However, it adds, encouragingly, “You can do it[!]”

Any mines in the state that accept tourists are required to be inspected daily for “proper ventilation, ground conditions and control, electrical hazards, general mine hazards, etc.,” according to the Colorado Division of Reclamation, Mining and Safety.

In a social media post, the local fire department said: “We are thrilled to hear all 12 people who were still inside the Mollie Kathleen Gold Mine have been safely rescued.“We’re grateful for the work of all first responders who ensured the safety of those still inside. Our condolences go out to the family who lost a loved one tonight, please keep them in your prayers.”