Alcatraz Island climate researchers have haunting experience staying in prison cells

SAN FRANCISCO -- A team of researchers who built a 3D map of Alcatraz Island to track erosion and the effects of climate change spent some spooky nights sleeping in the prison cells that housed some of the nation's most notorious criminals.

During their three-week stay on the island, the team slept in D Block, where prison authorities kept the most dangerous inmates. That meant no cushy mattresses, showers or heat. They used communal toilets and brought in their own food.

A few cells down from where lead researcher Pete Kelsey slept was the cell where infamous inmate Robert Stroud, the Birdman of Alcatraz, spent time. Kelsey's team had full access to areas that are off limits to daily tourists, including the hospital wing with its dentist office, X-ray room and infirmary.

The researchers also slept near the tiled cells with no furnishings where the mentally ill were held. Adjacent to these cells, a dismal shower that locked from the outside, keeping prisoners in.

"I did not like being in the hospital," said Kelsey. "That place gave me the willies."

Alcatraz Island is said to be haunted and, according to the team, it is.

Kelsey told CBS News Bay Area that, while most of his team snored while they slept, one member -- a retired law enforcement officer -- was exceedingly loud. Team members asked him if he would please sleep inside the mugshot room instead of D Block, which he agreed to do.

The next morning, as Kelsey went to retrieve the man to start the day, he found the team member outside the mugshot room, sleeping with his gear.

When the man woke up, Kelsey asked him what happened and the volunteer replied he would never, ever sleep again in that room, no matter what. The man explained that, in the middle of the night, he woke up to the sounds of a crowd of people in the room above the mugshot room. 

He said these "ghosts" were moving furniture around and a non-existent piano began to play. He grabbed his stuff, left the room, and refused to go back in. 

From that point on, everyone put up with the snoring.

The anecdote mirrors what others have reported about Alcatraz being haunted, with many visitors attesting they have heard unnerving sounds of moaning and crying coming from the cell blocks. Some say inmates and prison guards who died on Alcatraz over the years continue to haunt the island.

In addition, some Native American tribes believe the island was a place of malevolent spirits.