The citizens of Tucson are wondering about the loud noise they heard Wednesday night.
Described by various media outlets as a boom, Joe and Jane Public posted their thoughts at news websites, where some described it as sounding like an explosion.
One Tucson anchorman said the shock waves rattled the windows at his home in Marana.
Air Force bases in the area reported none of their activities caused the boom.
Since UFOS do not usually carry zombies, that leaves an invisible alien invasion. It's a reasonable assumption, right?