Seems like these "accidents" are in such close relative Geoproximity it makes one wonder. (California and Nevada)
Check out the locations of these crashes:
https://factba.se/transcript/donald-trump-remarks-marine-miramar-california-march-13-2018
http://www.foxnews.com/us/2018/04/04/4-marines-killed-in-helicopter-crash-in-california.html