(CHEYENNE, Wyo.) – The widow of a man killed by a grizzly bear in northwest Wyoming is suing the federal government. Yolanda Evert lost her husband Erwin during an attack in June of 2010 near Yellowstone National Park. The $5 million lawsuit alleges that bear researchers prematurely removed signs warning hikers of work they were doing nearby. The attack occurred where scientists had trapped and tranquilized the bear just hours earlier.