During updates or maintenance, the game is not accessible by any player, so attacking is impossible. Any attack will have occurred after the service break.

Although there is a short cool-down in place after maintenance that prevents anyone from attacking, we suggest you check from time to time to see if the update is finished. That way you could save yourself from getting attacked straight away. 

Meanwhile, we will do  our best to make our estimates of the maintenance break duration as accurate as we can.