A man shot himself to death Thursday at the main Houston airport after firing into the air with a rifle, witnesses and law enforcement sources told NBC News.
The man had a suicide note in a backpack, the sources said. They said he was fired on by federal agents before producing a handgun and killing himself.
It happened at Terminal B of George Bush Intercontinental Airport, outside of the secure area.
The NRA Annual Meeting is slated to open in Houston in less than 24 hours.