Two convicted murderers escaped from Iowa's only maximum-security prison last night, according to officials. The two inmates were last seen at 7 p.m. at the Iowa State Penitentiary.

Martin Moon, 34, had been serving a life sentence for murder since 1995. The other inmate, Robert Legendre, 27, was convicted of kidnapping and murder in Nevada. He was transferred to Iowa last year.

Officials are currently investigating how the inmates escaped and where they might have fled.