DANNEMORA, N.Y. (AP) -- Two convicted murderers used power tools to cut through steel and shimmied through a steam pipe to escape from a maximum-security prison near the Canadian border, leaving behind a taunting note urging authorities to "Have a nice day."

Escaped prisoners Richard Matt (L) and David Sweat (New York State Police)

The elaborate escape Saturday from an upstate New York prison had hundreds of local, state and federal law enforcement officers searching through the night for one man imprisoned for killing a sheriff's deputy and another who dismembered his boss.

Gov. Andrew Cuomo said Richard Matt and David Sweat staged "a really elaborate, sophisticated operation" that ended at a manhole cover blocks away from the prison - and must have been overheard by someone.

"They were heard, they had to be heard," Cuomo told ABC's "Good Morning America" on Sunday.

The men had filled their beds inside the Clinton Correctional Facility with clothes to appear as though they were sleeping. They left behind a note - a yellow square of paper with a smiling, bucktoothed face, along with the words, "Have a nice day."

Sweat, 34, is serving a sentence of life without parole after he was convicted of first-degree murder for killing a sheriff's deputy in Broome County, New York, on July 4, 2002. Matt, 48, is serving a sentence of 25 years to life for the kidnapping, dismemberment and killing of his former boss in 1997.

Steven Tarsia, brother of Deputy Kevin Tarsia, said finding out his brother's killer had escaped "turns your world upside-down all over again."

He said just the other day, he had been trying to remember the names of the men responsible for his brother's death, and "I couldn't remember their names.

"All of a sudden, I remember them again," he said.

The area where two convicted murderers used power tools to cut through steel pipes, and leave a note, at a maximum-security prison in Dannemora, NY (Darren McGee/New York State Governor's Office, via AP)

Tarsia told The Associated Press on Sunday he couldn't imagine how the men could have gotten power tools and escaped without help, but "I don't know why anybody would help them."

Roadblocks were set up in the area, which is about 20 miles from the Canadian border, and bloodhounds and helicopters were being used to track down the men, officials said.

Cuomo on Saturday called described the two as extremely dangerous. He asked the public to notify the police should they encounter the men.

"It's very important that we locate these individuals," he said. "They are dangerous and we want to make sure they don't inflict any more pain and any more harm on New Yorkers."

The two men's adjoining cells were empty during a morning check, said Anthony Annucci, the acting state corrections commissioner.

"A search revealed that there was a hole cut out of the back of the cell through which these inmates escaped," Annucci said. "They went onto a catwalk which is about six stories high. We estimate they climbed down and had power tools and were able to get out to this facility through tunnels, cutting away at several spots."

Investigators were probing how the men acquired the tools - and if any were missing from contractors at the prison.

Officials said it was the first escape from the maximum-security portion of the prison, which was built in 1865.

Canadian broadcaster CTV News reported that officials are concerned the men may attempt to enter Canada through Ontario or Quebec, and safety alerts have been broadcast to police officers in the Greater Toronto Area.

Sweat is white, 5 feet 11 inches, with brown hair and green eyes and weighs 165 pounds, police said. He has tattoos on his left bicep and his right fingers.

Matt is white, 6 feet tall, with black hair and hazel eyes, according to police. He weighs 210 pounds and has tattoos including "Mexico Forever" on his back, a heart on his chest and left shoulder and a Marine Corps insignia on his right shoulder.

Sweat and another man fired 15 rounds into Deputy Tarsia in 2002 shortly after using a pickup truck to break into a Pennsylvania woman's house, stealing rifles and handguns, authorities have said.

And nearly a decade after the 1997 kidnapping, murder and dismemberment of his former boss, William Rickerson, in upstate New York, Matt was returned to the U.S. from Mexico where he had fled to and, later, was arrested for fatally stabbing another American outside a bar in a robbery attempt. He was convicted in 2008 of Rickerson's death.

A family member of Rickerson reached by phone declined comment to The Associated Press.

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