joy. patient mom and her bundle of joy. today sunday, august 7, 2011. captions paid for by nbc-universal television live from studio 1a in rockefeller plaza. good morning. welcome to today on a sunday morning. i m lester holt. i m jena wolfe. we mourn the americans killed in yesterday s deadly attack in afghanistan. it s america s darkest day yet. a rocket propelled grenade struck a helicopter in the eastern part of the country killing 30 u.s. troops, 22 of them were navy s.e.a.l.s. reaction is still coming in from the front lines and from here at home especially on the base where many of the fallen live. we do know the attack happened during an operation in a taliban stronghold. it took place in a mountainous region that s becoming volatile. we have full coverage and we begin with atiaa abawi. reporter: officials continue to investigate just what went wrong and how yesterday became the most devastating day for american troops in afghanistan. 30 u.s. service m