SAN MATEO, Fla. -- A 66-year-old man is recovering after he was beaten by two teenagers armed with bats during a home-invasion robbery early Thursday morning, according to the Putnam County Sheriff's Office.

Deputies said Robert Lee Singleton was sleeping inside his home on Fern Street in San Mateo about 3:25 a.m. when he was attacked with baseball bats.

Singleton was airlifted to Shands-Jacksonville Medical Center, where he was in serious condition. Putnam County Lt. Johnny Greenwood said that Singleton was so bloody that deputies initially thought he'd been stabbed.

One investigator told Channel 4's Jim Piggott that Singleton was "nearly beaten to death."

Within hours of the beating, investigators traced a bicycle track that led them to arrest two teenagers. Detectives said they recovered the bats used in the beating along with Singleton's wallet and cash.

Dontress Caldwell, 19, and Roderick Spell, 17, were booked into the Putnam County Jail on charges of home-invasion robbery. The are both being held without bond.

Singleton's San Mateo neighbors said they didn't hear any commotion and are shocked by the crime.

"We been here for 32 years and never had a problem," resident Stevan Thomas said. "I wave at his daughter and Mr. Singleton right before dark."

"It's real scary because you think we're living in a safe neighborhood," neighbor Judy Marti told Channel 4's Jim Piggott.