Indianapolis Zoo officials are investigating how a cheetah managed to escape from its enclosure, spurring an hour-long lockdown of zoo guests while staff found and tranquilized the animal. Visitors to the zoo just west of downtown Indianapolis were told to seek shelter about 9:30 a.m. Sunday after the cheetah escaped. Zoo spokeswoman Judy Palermo says staffers found the cheetah named Pounce lying in a landscaped area outside its exhibit but still behind a barrier that kept it out of the public space. Zoo staffers used a tranquilizer dart to subdue the cheetah, which then ran back to its exhibit. The zoo's lockdown ended about 10:30 a.m. Palermo tells The Indianapolis Star (http://indy.st/1LRPUIW ) the zoo's cheetahs will be kept out of the exhibit until it's determined how Pounce escaped.