Americans Sam Burns and Max Greyserman were about to tee off at the first hole at 8:15 a.m. (1215 GMT) when the horn sounded to signal everyone should seek shelter.
World number two McIlroy, who won the Masters last month to complete a career Grand Slam, and third-ranked Schauffele, the defending champion and reigning British Open champion, were set to start at 8:25 and were on their way to the first tee from the practice area when the horn blew.
McIlroy, who has won four times at Quail Hollow, and Schauffele scrambled on Friday just to make the cut on the number at one-over par 143 and stood nine strokes adrift of leader Jhonattan Vegas of Venezuela.
Vegas was on eight-under 134 and set to tee off in the final pairing with France’s Matthieu Pavon, who shares second on 136 with South Korean Kim Si-woo and England’s Matthew Fitzpatrick. (AFP)
