In their place, the pair left decoys to trick guards into thinking they were asleep in their bunks -- and a yellow sticky note with a smiley face. It read, "Have A Nice Day!"
Despite a $100,000 reward and a manhunt involving some 250 law enforcement officials, Richard Matt and David Sweat -- both dangerous men who were serving lengthy sentences -- were still on the loose early Monday.
"They could be literally anywhere," said Maj. Charles E. Guess of the New York State Police, which is leading the search.
New York Gov. Andrew Cuomo told CNN on Monday that the pair must have had help carrying out the sophisticated escape. Authorities are focusing on civilian employees and contractors working at the prison, he said.