Scientists have 3D-mapped Alcatraz. What they’ve found may change how the monument survives the future

Scientist Pete Kelsey and his team have 3D-mapped the entire island of Alcatraz, discovering Civil War secrets, prisoner escape routes – and looking at ways to preserve the island for the future.

​ Scientist Pete Kelsey and his team have 3D-mapped the entire island of Alcatraz, discovering Civil War secrets, prisoner escape routes – and looking at ways to preserve the island for the future. Read More Breaking News, Latest News and Videos | CNN