Over the last 3 weeks I've played probably close to 2 hours total (real time), and in that time I've had 13 deathclaw attacks. I think it may have started because I exited the app during an attack, and somehow it became a loop. I defeat the deathclaws, then no more than 2-5 minutes later I get another attack. I haven't seen any raiders since I saw my first deathclaws. A friend of mine has the iOS app and he has never seen a deathclaw attack.
There needs to be an update where any vault door guards chase the intruders (raiders, deathclaws, etc) throughout the vault, or even an alert status where weapon-wielding dwellers in surrounding rooms call to arms.
I have almost 20 dead dwellers right now, as soon as I heal or revive some, another attack comes. This is ridiculous. Please help!

There are more strategies how to defend against deathclaws and it is totally managable. In my primary vault deathclaws do not even get to the second floor. Most important is having high-level dwellers with best weapons on the top floor and if possible, having their endurance maxed at first level (thy gain more HP when leveling, based on endurance). You can find topic about it in this forum too. Good luck!