chop4life wrote in post #5920922
I guess if i didnt use the flash it would not underexpose that much...., thats why i upped the EV a little bit to compensate the darkness, but it wasnt sufficiente enough... next time i should just shoot without the flash.
Thanks.

BTW, I neglected to say earlier welcome to POTN. I think that you will find this to be a helpful and friendly place to learn and share about photography.
Primarily, I think that the reason for the underexposure was due to using Manual exposure with the the aperture, shutter, and ISO values not adjusted to give the right exposure value. The fact that the flash was used is sort of a minor factor that might affect the outcome if it takes control of the shutter speed in order to have proper X synchronization, but usually will not be a problem.
One important tidbit about built-in flashes is to know their limitations -- they are tiny and generally only good for things like people shots within a range of about 3 to 10 feet from the camera. Also, because of their low energy, they are best when used only as "fill" lighting rather than being used as the primary light source. Finally, it is best if the primary light is not fluorescent because it is a significantly different color than the color of the flash. The problem that this causes is that areas that are in the shadows caused by the flash will be an ugly brownish green and the areas that are in the shadows of the fluorescent light will tend to be blue. However, the fluorescent lights normally do not have the distinct sharp edged shadows that the flash units produce since they are not point sources like the flash produces.
I hope that this answer is not too confusing nor too simplistic since I can tell that you already know a lot about using a camera's functions. Your shot has very good composition which shows that you are creative. Shooting sunsets can be a very challenging undertaking and camera metering systems often fail to respond correctly. One way to get a good exposure of a sunset is to use the shotgun approach -- shoot a number of bracketed shots to see which looks best. Sometimes, what might be considered the best in a technical sense, may not be what you want from a creative perspective. I will confess that I sometimes take dozens of sunset shots to try to get at least a couple good ones. Then I study the "bad" ones to try to see what could be improved.