A family on vacation was strolling along a street near Glacier National Park when Derick Madden plowed into them. Madden exited his vehicle, pulled out a shotgun, and opened fire, killing 39-year-old David Siau and his 18-month-old daughter, McKenzie. Madden used to date Christina Siau, who was with the family at the time of the attack. When he ran out of ammo, he pulled out a knife and started stabbing Christina. She was able to kill Madden, apparently with his own knife.