SAN BERNARDINO, Calif. (AP) — A couple whose gender reveal ceremony sparked a Southern California wildfire that killed a firefighter last year have been charged with involuntary manslaughter.

The San Bernardino County district attorney says Refugio Manuel Jimenez Jr. and Angela Renee Jimenez pleaded not guilty Monday to charges involving the El Dorado Fire.

The fire killed firefighter Charles Morton last September. Authorities say the family set off a smoke-generating pyrotechnic in dry grass at a park near Yucaipa, east of Los Angeles.

The blaze injured 13 other people and forced the evacuations of hundreds of residents. It destroyed five homes and 15 other buildings