credit for the attack. and america on alert. the manchester bombing outside the arena security perimeter is raising new concerns about a similar attack on american soil. how vulnerable are concerts and sporting events in the united states? i m wolf blitzer. you re in the situation room. we re following two major breaking stories this hour including critical new developments into the russia investigation. former cia director john brennan tells the house senate intelligence committee that he was aware of information and intelligence showing concerning and very deeply worrisome contacts between russian officials and individuals from the trump campaign. in a statement, the white house says, and i m quoting now, there is still no evidence of any collusion. on the other side of the capitol, the senate armed services committee questioned director of national