Arthur Andersen was a company that helped other companies with their money and finances. Imagine if you had a piggy bank and you needed help figuring out how much money you had and what you should do with it. Arthur Andersen would be the grown-up who could help you with that.
But something bad happened to Arthur Andersen. They helped a big company called Enron do a lot of bad things with their money. Enron was being sneaky and mean, and Arthur Andersen did not stop them. It was like if someone knew you were stealing cookies from the cookie jar and didn't tell your mom or dad. That's not good, right?
Because Arthur Andersen didn't do the right thing, they got in trouble with the law. They had to stop helping other companies and went away forever. That's why it's important to always do the right thing, even if it's hard.