On a New York City street the San Francisco rock group Death Angel strikes a macho pose for a photographer. These five teenage cousins of Filipino descent, wearing dark T-shirts and self-conscious scowls, attempt to appear forbidding. But they just can't hide their naturally sunny dispositions. A passerby takes one look and says, "What's this? Menudo goes Hawaii?"

Far from it. While Menudo makes the pubescent set swoon with sweet Puerto Rican pabulum, Death Angel's shtik is thrash metal, a primitive progeny of heavy metal and punk rock that since 1982 has won over adventurous teens with violent guitar strumming and drum pounding performed at breakneck speed. Their debut album, The Ultra-Violence, includes such songs as Mistress of Pain and Final Death, a rumination on nuclear holocaust. Though none of the boys has yet turned 20, Death Angel is now on a 30-city U.S. tour and has already been accepted in the thrash metal pantheon. "Their music is about life, about the cruelty of the world," explains one fan. "So many metal bands strive only to play fast, fast, fast!" says Death Angel's drummer, Andy Galeon, 15. "We like to do stuff you couldn't play if you weren't paying attention."

Death Angel was born in innocence five years ago when the group's lead guitarist, Rob Cavestany, then 13, learned a few chords and started jamming with Dennis Pepa, 14, on bass, Gus Pepa, 14, on guitar, and Andy, 10. Three years later Mark Osegueda, then 16, was recruited from his school choir to sing lead vocals. "My dad wasn't into the idea of me being in the band at all," recalls Mark, an ex-football jock at Concord's Clayton Valley High. "He was thinking, 'Okay, football scholarship at Notre Dame...' Now he's so proud it's almost sickening."

Adopting a name to match their taste for the nihilistic music of such metal bands as Kiss and Black Sabbath, Death Angel attracted a cult following by playing local clubs, then appearing as opening act for the big-time thrash band Metallica in 1985. The next year they signed their record deal for The Ultra-Violence, which has sold 40,000 copies in four months.

Opening for the star thrash band Exodus in New York a few weeks ago, Death Angel delivered an ear-shattering performance that inspired fans to hurl themselves violently at the stage. Sweaty but elated at the set's end, Mark raised a fist and screamed, "We'll see you next time! AND WE WON'T BE OPENING!" Then, as their decibel-dazed fans shrieked on, the teen heroes went backstage and partied—with pizza and soda.