WAUKESHA - Federal officials say pilot error caused a twin-engine plane crash that killed four Wisconsin men in Michigan's Upper Peninsula. The August 2006 crash killed Spancrete executive Daniel Nagy, company employees Michael Wraalstad and James Wehr, and pilot Nicholas Gerger. The Spancrete Group Inc. of Waukesha provides precast and pre-stressed concrete for structures worldwide. Nagy was the grandson of the company's founder. A National Transportation Safety Board report released Monday says Nagy was getting flight instruction from Gerger when the plane crashed into the outer perimeter fence of the Chippewa Correctional Facility in Kincheloe, Michigan. The report says the pilot didn't stay in control of the plane while circling for a landing and did not abort the landing when he should have. (Copyright 2008 by The Associated Press. All Rights Reserved.)