a tragic end after a mother s trip to mexico with friends to get a medical procedure. now two in the group are dead. two others found alive. how the group got lost and ended up in the hands of armed criminals. plus i m taking over this plane. taking over this plane, he says. terrifying moments on a cross-country flight when a man threatens to hijack the plane. the video as freaked out p passengers tried to react. plus, cnn s upclose look at how the chinese will go to control its country s messaging. welcome to the lead. and we start today with our world lead and new details in tin vest game into those four americans kidnapped in mexico last week. local officials say one person has been detained after two of the u.s. citizens were found d dead. the two others are thankfully alive, though one is severely injured, according to a u.s. official, and those two have returned to the united states for medical treatment and observation. family members say that the four were