LINCOLN, Neb. (AP) – Gov. Dave Heineman is encouraging Nebraskans to fly U.S. and Nebraska flags at half-staff. The flag-lowering on Sunday is part of the annual National Fallen Firefighters Memorial Service. The remembrance honors firefighters and other first responders who have sacrificed their lives to save others. The National Fallen Firefighters Foundation says 72 firefighters nationwide died in the line of duty in 2010. A plaque with their names will be added to the national memorial over the weekend, along with 17 firefighters who died the previous year. The plaques surrounding the Memorial will contain the names of more than 3,400 firefighters.