"But a source briefed on that device and the one sent to CNN told The Post on Wednesday that they couldn’t actually have blown up because neither was equipped with a blasting cap or other means of detonating explosive material."

“There was nothing to ignite it,” the source said. “There was nothing there.”

https://nypost.com /2018/10/24/bomb-sent-to-cnn-came-with-envelope-of-white-powder/