Offering the closing prayer at the National Prayer Breakfast on Thursday, astronaut Mark Kelly said his wife, Rep. Gabrielle Giffords, "continues to improve" each day and that the past month "has been the hardest of my life and the hardest time of my family's life." The Democratic congresswoman was shot in the head last month while meeting with constituents in a Tucson, Ariz., shopping center. Kelly said he hopes the "horrible and tragic" shooting that left six people dead "was not merely random. That maybe something good can come from this." He also encouraged Americans to "work better together."