Fentanyl 11. He said, “that’s pretty high.” This level of fentanyl can cause pulmonary edema. Mr. Floyd’s lungs were 2-3x their normal weight at autopsy. That is a fatal level of fentanyl under normal circumstances. . . . AB said that if Mr. Floyd had been found dead in his home (or anywhere else) and there were no other contributing factors he would conclude that it was an overdose death. MORE & AUDIO