Game: League of Legends; Failed to Connect to the server.

I was playing LOL then logged of to get something to eat. After that I went back to play again. I was in the middle of the game when it crashed. I tried to log in and this message appeared. I tried the firewall but still it fails to connect. What could be wrong? In between the time I logged of and logged in again there was no one using the computer.

League of Legends
Failed to Connect
Unable to connect to the server. If you have a firewall, it may be blocking the connection. Please refer to your firewall’s documentation. Would you like to retry the connection?
