Just six players managed to complete their final round - with Rory McIlroy putting the finishing touches to his when the siren sounded for the first time.
Some players did return after a delay but the skies opened once more and, with greens soaked with falling water, everyone was told to go home and return on Monday.
Twenty-two players had yet to swing a club at that point, with leader Jim Furyk now facing an overnight wait before he can pursue the title.
McIlroy did manage to finish, though, and signed off with a relatively promising round considering his form this year and at this event.
The Northern Irishman carded a three-under 68, meaning he finished seven over for the week. That he was 20 shots behind a still-to-play Furyk shows how much work he still has to do.
Other than McIlroy, Kevin Chappell, Dustin Johnson, Lee Westwood, Charley Hoffman and Scott Piercy also finished, with Westwood no doubt keen to move on from a three-over round which topped his tournament score up to 12 over.