to figure out who is responsible, who organized it. who armed, who bought. who financed these attacks. the situation is extremely tense as you can imagine. residents are told to stay inside. let s bring in our senior engineer correspondent mellissa ward. she is not far from where i m standing, near the concert hall. what are you learning? what is the latest on the investigation in. reporter: well, hala, you heard president francois hollande saying there is an attack by isis. isis has come out online and released a statement. it bears all the hallmarks of other isis statements. and they talk about the battle of paris. they say eight suicide bombers struck at the heart of france s crusaders. they call them soldiers of the caliphate. it says they were sent to act on