Have you done anything that was different of your maintance routine before you start noticing any changes? A full tank shot and shots of individual can help us figure out what is wrong with your tank

Here are some shots from today

Sad Corals 

Here is my carbon bag and now I have a new question.  Is this a bad starfish I found on it?

Rest of the corals look healthy. only those three on the other pictures are dying. shoot could it be just the corals? how long did you have them?

http://www.chucksaddiction.com/coraldisease.html - http://www.chucksaddiction.com/coraldisease.html

Burrowing Worms :  While unable to obtain the actual organism that created the below problem, it is apparent due to the formation of calcified tubes that a worm species is most likely the cause.  As this pest species first infests a coral colony, it first builds its own structure on top of the corallite's walls, which block light and water flow to the underlying polyp.  The polyp then slowly dies over the course of weeks and months allowing these and other organisms to further colonize the coral skeleton substrate, effectively killing the coral colony little by little.

   Formation of dead and soon to be dead areas on the coral colony.  Even in seemingly healthy areas of the colony, these organisms are already present as individual formations on top of the corallites.  In the most affected areas, the organism has burrowed through the walls of the corallites.