al1~

Shows how good school computers are.
That comment is irrelevant. This is a public site that anyone can find and access. If you are open to the public you are very vulnerable to a DoS attack.

Your only real defence is to have sufficient resource to handle the traffic. Even Microsoft's update servers creak when a new security patch comes out.

You don't spend masses of money on that kind of set-up, you just take the site down and deploy the forces of darkness to deal with the little toe-rags causing the problem. That is exactly what they have done here.