Mexico City's mayor expressed outrage Saturday that youths as young as 13 were among the dozen people killed in a nightclub stampede and said the officials involved in the police raid that sparked the crush had been suspended. Police went to check reports of underage drinking and drugs in the News Divine club in a working-class Mexico City neighborhood Friday evening, causing hundreds of customers to try to flee the club. About 500 young people - more than the club's capacity - had packed the bar to celebrate the end of the school year, according to police. Witnesses and police said the only emergency exit was blocked, and desperate customers tried to break out windows to escape the crush. "The city is indignant," Mayor Marcelo Ebrard told a news conference. "What we saw yesterday was ethically unacceptable." City prosecutors said three young teens - ages 13, 14 and 16 - were among the nine students and employees who died. Three police officers also died at the club in Mexico City's Nueva Atzacoalco district. A dozen people were injured in the stampede, three seriously, said city prosecutor Rodolfo Felix Cardenas.