Correction d'erreurs d'une réponse à une question sur le terrorisme.

Sujet du devoir

Bonjour, j'ai un devoir à faire. Je dois répondre à la question : "what do you think of the 11/9 attacks and their impact ?" (200 mots)
J'ai déjà écrit mon texte mais j'aimerai que quelqu'un puisse me corriger les fautes d'orthographe, de grammaire et surtout de conjugaison et si vous pensez à des choses essentielles que j'aurai oublié de parler ou que je devrais enlever de mon texte!

Je vous remercie d'avance
Bonne journée

Où j'en suis dans mon devoir

On september 11th, 2001, America was hit by terrorists attacks.
When the Twin Towers collapsed, I was 6 years old and I didn't understand the importance and consequences of what had happened. I thought it was just the collapse of two towers, I did not know that this was a terrorist attack, I was too young to understand.
Today, I think this is inhumane terrorist act. I'm upseted by 3000 people who's dead and for people have lost a husband, wife, child, parent, friend ...all of them are now dead innocence in vain.
The world tribute to those people who died as with the "Patriot Day".
The attack still has a big impact now as it has frightened the world and changed the world view.It's a important and tragic event on the 21st century. Impacts are large...
The impact is economical because it caused an important slowingdown. But the impact is also and above all moral.
The purpose of destroying the Twin Towers was primarily to scare America. It was a success, unfortunately.
People are petrified, frightened, live in fear despite the many precautions taken to tighten security (as Noble Eagle) and eradicate terrorism that has killed innocents for prevent another tragedy, which caused a deep trauma everywhere in the world.