David Wilkerson is prophesying an imminent "earth-shattering calamity" – and he’s calling it the judgment of God.

Author of "The Cross and the Switchblade,” Wilkerson is predicting something major will happen in New York City and spread across the country and around the world.

In his blog, Wilkerson says he was "compelled by the Holy Spirit to send out an urgent message" to those that follow his ministry.