Well, our Declaration of independence states so... and it is a legal document.
"We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness."
I don't think the Declaration of Independence is a governing document. Our governing document is the Constitution, which says you can lose your right to life:
The Fifth Amendment to the United States Constitution says:
“ No person shall be ... deprived of life, liberty, or property, without due process of law .... ”
The Fourteenth Amendment to the United States Constitution says:
“ No State shall ... deprive any person of life, liberty, or property, without due process of law .... ”