How can you die from lockjaw?

Tetanus. In the past, the painful hypercontraction of all muscles made breathing impossible. The tetanus bacillus, unlike most bacteria, grows best in dead tissue and used its toxin to kill its victims. Today, it is easy enough to paralyze the sufferer and put them on a ventilator until the disease passes. You still do not want to get tetanus.
Yes. Lock jaw is a lay term for tetanus. This is a serious, life threatening infection. There are no home remedies. It can be fatal.