A 21 YEAR-OLD MAN WAS INJURED IN WHAT APPEARED TO BE A BRAWL, THAT BROKE OUT BETWEEN RIVAL GANG MEMBERS IN WATSONVILLE THIS AFTERNOON. ABOUT 20 PEOPLE ARE SAID TO HAVE BEEN INVOLVED IN THE FIGHT, THAT TOOK PLACE AROUND 5:15 P.M. ON THE MAIN STREET BRIDGE OVER THE PAJARO RIVER. THE INJURED MAN WAS AIR-LIFTED TO A BAY AREA TRAUMA CENTER WITH LIFE-THREATENING WOUNDS.