Is the U.S. ready for “the really big one”?

A natural disaster of titanic proportions is overdue to strike the U.S., physicist Michio Kaku warns.

Seismologists predict it will be the worst natural disaster in North American history, and the federal government estimates it could contribute to 13,000 deaths and 27,000 injuries.

“It’s not a question of if, it’s a question of when,” the City University of New York physics professor said Thursday on “CBS This Morning.”

A devastating earthquake and subsequent tsunami, dubbed “the really big one” in a New Yorker article of the same name, is destined to strike a fault line called the Cascadia subduction zone that runs for 700 miles off the Pacific Northwest coast from Vancouver through parts of California.