LOS ANGELES — Three people must stand trial for a Los Angeles apartment fire 24 years ago that killed 10 people — seven of them children.

A judge on Friday ordered trial for gang members Ramiro Valerio and Joseph Monge and for Johanna Lopez. They’ve pleaded not guilty to murder charges that could carry the death penalty.

Authorities said the three set a mattress on fire in a 40-unit Westlake apartment building in 1993 because the manager had tried to stop drug dealing there.

Smoke and flames spread through the complex.

The residents, most of them poor immigrants, jumped from windows or climbed down bed sheets to escape and formed a human chain to bring down children.

Seven youngsters died along with three women — two of whom were pregnant.