Game freeze

We started a regular starting summoners rift, when it appeared (prepare yourselfs the battle is about to begin) the game froze and we were on this screen for 1 minute and then appeared black screen and crashed the game ,when we reconect crashed the game too,after some time It went down and we didnt played more (went to the home screen LoL) not only happened to me but also to all players in the game (we were on call skype), was the first time it happened.we could do what we wanted when the game froze (write chat and change the runes ...). it was kind of weird, but we could take a punishment for having not played, so fix this please. Thank you for your attention.