About 10 people who were involved in one way or another regarding Watergate were on the plane that crashed killing E. Howard Hunt's wife

This is one reason why this crash is so suspicious because you can see how the government might have channeled all these people (one way or another) onto this plane to get rid of them. Also, this crash was swept under the carpet by the government which is why you likely haven't heard of it. However, President Nixon might have just been trying to cover up everything that had happened by getting rid of people who might "talk" which makes sense to me too understanding those times.

We were still in the middle of the Viet Nam War in 1972 and so there were many factors involved in this WARTIME consciousness similar in their own ways to World War II and the Korean War. So, it makes perfect sense to me that Nixon (or his underlings) would kill people in order to prevent them talking. I think Trump is like this too which is why so many Republican Lawmakers are afraid of contradicting him about anything. They know he has enough money to have them or their families killed and likely has had people killed along the way when you watch how he operates. 

These kinds of things happened a lot when J. Edgar Hoover was in charge of the FBI. Many people still believe J. Edgar Hoover sanctioned the Assassination of President Kennedy and Martin Luther King. Those were scary times in some ways much like the times we live in now.