What do you mean by 'and?' I don't get it.
It's not a shooting, it is a bombing; a suicide bombing no less. In the US. You don't get bombings in the US. Esp. not suicide bombings. In a caricaturised expression, 'it is not allowed'.
Shootings are different, because guns are different. It's very profitable and also beneficial from various points of view. It's deep in the culture, history...etc. It's even needed and practical. Most of your country is uninhabited open space. In short, you kids are allowed to play with your guns all around, daddy doesn't care about it.
Bombings are not any of the above. Nobody is allowed to play with bombs. Bombing is a direct, open attack -doesn't matter where it comes from- on American soil from American military point of view and that is one thing that will be prevented at any costs. That's the foundation of the power of US fed state has on its people. Preventing any kind of direct attack; in this case bombing, is the best thing they can do because 'only' they can do, which they have done for the last 40 years or so. (9/11 is not a bombing.) Which is a power akin to sending drones around the world to eliminate targets. In short, you don't lose that power, don't let anyone breach it, because you can't. Otherwise, it would change everything.