JACKSON, Miss. -- Officials say a prison for illegal immigrants in Mississippi was on lockdown after a riot that began on Sunday left one guard dead and at least 19 people injured. All inmates were secured in their housing units by 2:45 a.m. Monday, nearly 12 hours after the disturbance began at the Adams County Correctional Center in southwest Mississippi, Mike Machak, a prison spokesman, said in a statement, according to WDSU-TV, an NBC News affiliate in New Orleans. Officials haven't released the identity of the slain guard. Machak said 16 other employees were treated and released from a hospital...