I'm trying to remember the name of an Anime I watched when I was younger. The main character is a male teenager who as a kid had his building blow up for an unknown reason. He is attacked by some monsters an some steps. To make a long story short, the main character finds out that the people who survive the apartment building destruction all have a piece of the box that will stop the stuff from happening. If anyone can tell me the name it would be great. If you need more details tell me and I'll include them.