Explosion at California medical facility appears to be intentional act, source says

Explosion at California medical facility appears to be intentional act, source says  CNN Blast at California building that killed one may have been intentional, sources say  NBCNews.com 1 Dead, 3 Hurt In Suspicious Explosion At Southern California Office Complex  NPR Woman killed in 'suspicious' explosion at Aliso Viejo office building  Los Angeles TimesFull coverage