It's only happened 3 times:
Known one-point safeties:
1. Westminster vs. West Liberty State (NAIA Division II), September 7, 1996.
Westminster holder Kevin Freeman fumbled the snap. Abandoning the kick, he rolled to his right, but threw an interception, which Liberty caught on the 1-yard line. The interceptor was immediately tackled, causing a fumble that Liberty recovered in its own end zone.
2. Moorpark College vs. Bakersfield (Junior College), September 21, 1996.
Moorpark kicker Tim Wolleck's extra point was blocked and recovered by a Bakerfield defender at the 3. The defender retreated into his own end zone, and was tackled there.
3. Texas vs. Texas A&M, November 26, 2004.
Texas had just scored a touchdown off a blocked punt to cut Texas A&M's lead to 13-12 in the 3rd quarter. The snap on the extra point was low and was bobbled by backup holder Matt Nordgren, causing Dusty Mangum's kick to be blocked. A Texas A&M player picked the ball up but was immediately tackled and fumbled the ball into the end zone, where it was recovered by another Texas A&M player.
This one is on
Youtube . Forward it to 1:16:07