A Level 10 Alert is a warning that alerts something very bad is happening. It seems to have been first created by Dr. Light, and used in the Prelude to a Bad Time when Bass traveled back in time and altered the time line. When it goes off, it fills the room with red light and blares the phrase "WARNING! This is a Level 10 Alert!" Proto Man then verifies that there's nothing lower than a Level 10 Alert. It is uncertain if there is anything higher. Variations of the Level 10 Alert have been used by other characters throughout the comic strip.