The State Department is warning Americans presently in Mexico to shelter in place amid the chaos wrought by the death of Nemesio Rubén Oseguera Cervantes, the Cartel kingpin known as "El Mencho." In advisory issues this week, the State Department is recommending United States citizens reconsider any upcoming trips to Mexico they may have planned. Americans who are already in Mexico - either as residents or tourists - are being urged not to travel anywhere in most of the country's 31 states. The Mexican army, using intelligence provided by the U.S.