Last night in my area we had a bad storm when we were sleeping, and because I keep my phone in DND mode at night I didn't receive any sort of audible alert despite having the "Override Do Not Disturb" checked. This is because the Wireless Alert technically doesn't have a notification sound, it has some other type of sound (not media either) that is being blocked by DND. You can't adjust these notification settings, as the OS prohibits you from changing Wireless Emergency Alert settings. This is potentially a big issue - I don't want to miss and incoming Tornado alert because my phone is on DND mode. Google needs to sort this out.