I searched around in here a bit and couldn't find it so I don't know for sure if this was posted before or not.
Looks like it was a home invasion during a small party with 10 occupants. 2 armed guys burst in. 1 of the occupants drew a handgun and opened up on them. The other attendees of the party are crediting that lone person that fought back with saving their lives. Although, it looks like one other person besides the BG's was hit in the crossfire. It doesn't say whether it was the BG shot or the GG shot that hit the bystander.