The avian flu strain H5N1, which first emerged among migratory birds, is now affecting dairy cattle and a major egg producer in Mississippi, with one person infected; polling in Israel shows support for the government's war on Hamas but disapproval of Prime Minister Benjamin Netanyahu; NATO celebrates its 75th anniversary, with Sweden attending its first meeting as a full member and discussions on a new five-year plan and Ukraine's membership; NPR's Investigations Team analyzed the collapse of the Francis Scott Key Bridge in Baltimore, revealing communication difficulties during the rescue operation; tipping has become more confusing with electronic payment software, and location and communication are key factors in deciding how much to tip.