A 6-year-old girl died at the Glenwood Caverns Adventure Park in Glenwood Springs, Colorado, on Sunday night following what park officials described as an incident on its Haunted Mine Drop ride.

The exact details surrounding the fatality on the ride, which plunges passengers 110 feet down into a pitch-black tunnel, remain unclear.

The girl was on vacation with her family from Colorado Springs, per NBC . Her name has not been released.