The owner of a downtown Las Vegas apartment building and an associate are being charged with involuntary manslaughter and criminal neglect for a fire last December that killed six people. The Alpine Apartments blaze was the deadliest residential fire in city history. The Clark County district attorney said Thursday that Adolfo Orozco-Garcia and Malinda Mier each face 21 felony charges that, combined, could put them in prison for nearly 50 years. Neither has been arrested. An attorney representing Orozco in several civil negligence lawsuits did not immediately respond to messages. It’s not clear if Mier has an attorney.