Olympic divers arrived to a closed pool as officials took more time to clean the green-tinged water before holding the first individual event of the Rio Games.
The water suddenly changed color Tuesday, midway through the synchronized diving events. Officials insisted the water was safe for competing, even after a larger, adjacent pool used for water polo and synchronized swimming also turned a lighter shade of green.
The diving well was shut down when athletes arrived for morning warmups, though it did finally open at 1 p.m. local time — just 2 1/2 hours before the start of the women's 3-meter event.
Eighteen of the 29 divers qualified for Saturday's semifinals, including Americans Abigail Johnston and and Kassidy Cook. Johnston finished sixth overall with a score of 333.60, while Cook recorded a scored of 327.75, good for eighth.
Canada's Jennifer Abel's scored of 373.00 was the day's best.
The water color appeared to be closer to normal but was still shaded green.
American diver Abby Johnston, who is competing on the springboard, said she showed up for her warmup, only to learn the pool was shut down without any notice. She wrote on Twitter that "#FixTheSwamp" should start trending.
British diver Tom Daley, who won bronze in the synchro platform event, also commented on the state of the pool in a Twitter post.
"Hopefully that means we haven't been diving in anything too bad the last couple of days!" Daley said.
Mario Andrada, chief spokesman for the local organizing committee, stressed that the pool was safe for competition, clearing the way for the 3-meter preliminaries. He conceded that some athletes were bothered by the water, but said that was a result of efforts to clean the pool.
"We reiterate what we have been saying all along — the water does not offer any threat to the health of the athletes," he said. "In the first day of this water situation, one or two athletes complained about their eyes being itchy. This was a result that the first reaction when we saw the water turning green was to use one of the chemicals — chlorine — that is very common in swimming pools. We reduced immediately the quantity. We retested the water and it was totally within the parameters."
Simon Langford, chief spokesman for the Maria Lenk Aquatics Center, said the pool was closed to allow additional cleaning. He said the decision was supported by world governing body FINA.
"The reason is that the water must be still so the pool can return to its blue color as soon as possible," Langford said in a statement.
Andrada said officials were caught off guard by the pool's deteriorating condition.
"Chemistry is not an exact science," he said. "Some things, as you can see, went longer than expected."
Rain the past couple of days made it even tougher to get the water color back to normal.
"The rain doesn't help," Andrada said. He added that athletes had access to dry-land training in the morning, but conceded that "was not ideal."
He explained that the changing color of the pool was the result of increased alkaline levels, much like aquarium water can turn green when not monitored properly.
"When we went to fix the green, there was a discussion about the best chemicals. We can't use too much chemicals in the water because athletes are training in it," Andrada said. "We certainly could have done better in the beginning to prevent the water from turning green. Once it turned green, we again made another bit of a mistake."
AP Sports Writers Jay Cohen and Steve Wade in Rio de Janeiro contributed to this report.