Possibly asleep. Sounds like the girls took the ATV without permission.
update - they don’t know how they got in the shaft.
Girl, 13, found dead in Ariz. mine shaft
http://news.yahoo.com/s/ap/20070902/ap_on_re_us/mine_shaft_rescue;_ylt=AqZGiYWGiD142T5IIEa9Vwqs0NUE
CHLORIDE, Ariz. - A 13-year-old girl who went missing while riding an all-terrain vehicle was found dead in a mine shaft, while her 10-year-old companion was rescued with serious injuries early Sunday, authorities said.
A rope team descended into the vertical shaft, where the teen was found dead, sheriff’s spokeswoman Sandy Edwards said. Efforts were under way to remove her body.
Edwards did not know how the girls got into the mine or how far down they were. She also did not know the girls’ relationship.
The pair went missing about 7 p.m. Saturday and never came back. Officials discovered they were in the shaft about 6:20 a.m. in Chloride, about 17 miles north of Kingman.
The 10-year-old girl had “major injuries” and was being transported to University Medical Center in Las Vegas, Edwards said.
(This version CORRECTS it’s not clear how the girls got into the mine.)