[greglepore]

It was a "plug" in the sense that its a sealed exit that used on some airlines with higher capacity than Alaska specs their planes. On Alaska, its "sealed" with no interior access. Somehow it blew out.
And yeah, they were lucky. The other incident 930 referred to was the SW that had an engine come apart over Philly, debris took out a window and yes, the passenger got sucked partway out and beat to death.