dramatic rescues from the rising waters, today, saturday, dramatic rescues from the rising waters, today, saturday, august 6th, 2011. captions paid for by nbc-universal television good morning, everyone. welcome to today on a saturday i m lester holt. and i m jenna wolf. amy robach has the morning off. we re going to start with a devastating morning in afghanistan. it is the deadliest incident for americans in this decade-long war. the taliban claimed responsibility for the attack on that chopper that s killed dozens of americans. most of them, we re told, part of u.s. special forces. we ll get more in a live report from kabul in just a few minutes. the other big story overnight, the u.s. credit rating, standard & poor s is the agency that advises investors on long-term security lowered america s credit rating from aaa to aa-plus. it has never happened before. it s all about how the country will pay for its debt, and s&p pointed the finger at washington. so