Qualifying at the Sao Paulo Grand Prix has been postponed until Sunday as a result of heavy rain.
The session had been due to start at 18:00 UK time (15:00 local) on Saturday.
A decision was finally made at 16:45 local time on Saturday, after a series of delays, that the track was too wet and conditions were not going to improve.
Governing body the FIA said a decision on a new start time would be made “as soon as possible”.
Formula 1 president Stefano Domenicali said: “The conditions are not safe to drive, as simple as that, and there is a problem also of light that very soon will hit the track.”
Sunset is at just after 18:00 local time in Sao Paulo.
Domenicali’s interview with F1’s official television channel was interrupted by Lewis Hamilton, who said: “I want to go out. If you give us better wet tyres, we’d be able to go out in this.”
A spokesperson for governing body the FIA said: “The decision was taken because of the lack of visibility caused by the level of rain we have experienced in the past few hours.
“There is a lot of standing water on parts of the circuit, which renders conditions unsafe.
“As much as we would all like to see competition on track, the safety of drivers, team members, volunteers, officials and spectators is our main priority.”