BEACH CLOSED DO TO SHARK SIGHTING should be changed to BEACH CLOSED DUE TO SHARK SIGHTING.
The word "do" should be changed to "due." The two words my sound almost alike but the meaning is very different. "Do" means to act or perform while "due" means because of or as a result of. So, the meaning of the warning is: the beach is closed because sharks were seen within the area.
