The word 'leak' has its own meaning in politics, and plenty of political careers have been killed by leaks of information.

But Sen. Mark Pryor (D-Ark.) revealed that another kind of leak almost killed him years ago.

During a Senate hearing on Thursday, Pryor said that shortly after law school, he lived with a life-threatening carbon monoxide gas leak emanating from a hot water heater in a house he shared with two roommates.

"One of my roommates, his bedroom was just a few feet down the hall from a bathroom," Pryor recalled, "and it had a hot water heater ... and the carbon monoxide was just leaking out of that hot water heater.

He added, "we had no idea."

And the men would have likely remained clueless if the odorless, invisible toxic gas hadn't finally made his roommate sick enough to seek help. "He's getting these flu-like symptoms -- headaches, you know, the whole thing."

Pryor still doesn't know how his roommate figured out the cause of his symptoms, saying only that the guy "knew something was wrong and he figured it out."

The three men replaced the water heater, installing a new one "properly, with the right venting and everything," said Pryor.

But, he said, the leak could easily resulted "in a tragedy."

"It was a near miss."