descend on waco. heading to this busy shopping plaza an the twin peaks restaurant. which advertises bike nights, posting on facebook, "ladies and gentlemen, start your engines." 11:00 a.m., twin peaks opens for business. about an hour later in the restroom, a fight breaks out. the brawl spilling into the parking lot. the bikers involved using brass knuckles, knives, chains, clubs and guns. >> i just got a call from a passerby, they were going by twin peaks, thought they heard a gunshot, looked over and saw a lot of people running. >> reporter: people hiding in nearby restaurants watch as 22 officers rush into action. >> it was really, really scary. they said people outside the doors had guns. i crawled back toward the freezers with a lot of the waitresses. >> reporter: parents, carrying their children to safety. police and bikers exchanging gunfire. nine gang members killed, another 18 injured. 170 arrested. cops lining them up on the curb and loading them into buses and squad cars.