SIOUX FALLS, S.D. (AP) - South Dakota corrections officials say staff at the State Penitentiary in Sioux Falls thwarted a planned escape attempt.

Authorities say the escape was planned Tuesday during a medical transport of inmate Silver McClanahan, who is serving a life sentence for first-degree manslaughter in Brown County. He's been in prison for nearly two decades.

Corrections officials say penitentiary staff learned of the plot and alerted security officers, who prevented the escape attempt.

A criminal complaint has been filed against McClanahan and against former inmate Lloyd White Face, who is on parole in the Sioux Falls area on grand theft and rape convictions in Pennington County.

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