KAZAN, Russia (AP) So much for the U.S. swim team's plan to kick off the world championships with a strong performance in the 4x100-meter freestyle relay.
The American men didn't even qualify for the final.
The U.S. squad of Jimmy Feigen, Anthony Ervin, Matt Grevers and Conor Dwyer tied Germany to win the final heat but placed only 11th overall - missing out on the eight-team final later Sunday.
In 15 previous worlds, the American men have won this relay 11 times - although not once since 2009. The only other time they didn't make the final was back in 2001 in Fukuoka, Japan.
So what happened?
''Honestly don't know,'' Ervin said. ''Jimmy looked pretty good coming in, I felt good going out. I died real bad at the end of my leg, which is not uncommon. I didn't really see the rest of the relay, I was still kind of rolling around in a bit of a lactic acid blackout.
''We're stunned by the overall results. Just got to go back and analyze it,'' Ervin added, leaning over and gasping for air. ''We all thought we were feeling good and confident. We thought we were going to send a little bit of a message this morning.''
Host Russia, featuring sprinting standout Vladimir Morozov, topped the heats in 3:12.46. That sent the crowd of nearly 10,000 inside the Kazan Arena into a frenzy. Fans banged white inflated tubes together and waved Russian flags around the temporary pool, which is set up inside a football stadium.
Brazil qualified second, Italy third and defending and Olympic champion France was fourth. The U.S. was more than 3 1/2 seconds off Russia's time. Australia, without the injured James Magnussen, also failed to advance in 13th.
Fortunately for the U.S. team on the opening day of the traditional pool events, teenager Katie Ledecky was there to pick up the pieces by flirting with her own world record during the 400 free heats.
And the U.S. women's team of Shannon Vreeland, Abbey Weitzeil, Margo Geer and Lia Neal led the 4x100 free relay heats - despite a scoreboard mix-up that initially had them racing in place of Hong Kong in the opening heat.
The 18-year-old Ledecky was nearly half a second faster than her mark set last year midway through the eight-lap event before easing off to still lead her heat by more than two body-lengths in 4:01.73.
Ledecky has already established two world records in the 400 free, having swam 3:58.86 at last year's U.S. trials and then lowering it to 3:58.37 at the Pan Pacific championships a few weeks later last August.
Another record seems within reach in the final later Sunday.
''That race is pretty much all adrenaline based, so I wasn't focusing too much on things. I probably went out too fast,'' Ledecky said. ''Just need to move on. I think I'm set up pretty well for tonight.''
Ledecky's closest challenger in the heats was Jessica Ashwood of Australia, who touched in 4:04.47.
Camille Muffat of France, the Olympic champion in the 400 free, was killed in a helicopter crash in Argentina in March.
This is the first of four individual events for Ledecky, who will also enter the 200, 800 and 1,500 free.
Britain's Adam Peaty also appears poised to improve his own world record in the 100 breaststroke.
Peaty, who burst onto the scene over the last year, led the heats in a meet record 58.52 - not far off his mark of 57.92 set in London in April.
Olympic champion Cameron van der Burgh of South Africa qualified second in 58.59.
Semifinals are scheduled for later Sunday with the final Monday.
''I was a bit more nervous than usual. That's like a final crowd out there,'' Peaty said. ''I did a lot of work on that front end to keep it as relaxed as possible. I'm kind of excited.''
In the men's 400 free, China's Sun Yang was fastest in his first major event since his doping suspension was revealed.
Sun touched in 3:44.99, winning his heat just an arm's length ahead of Britain's James Guy, who qualified second in 3:45.37.
After seeing his time, Sun gave a thumbs-up.
Ryan Cochrane of Canada was third in 3:45.86, while Australians Mack Horton and David McKeon failed to make the eight-man final.
China's anti-doping agency revealed in November that Sun served a three-month ban earlier that year after testing positive for the banned stimulant trimetazidine.
Sun won the 400 free at the last two worlds plus the 2012 London Olympics.
Defending champion Katinka Hosszu of Hungary, nicknamed the ''Iron Lady'' for her success across multiple events, led the 200 individual medley heats in 2:07.30. Olympic champion Ye Shiwen of China was only fifth in 2:11.23.
Hosszu may swim up to seven individual events in the eight-day meet.
Sarah Sjoestrom of Sweden qualified first for the 100 butterfly semifinals in 56.47. Olympic champion Dana Vollmer of the U.S. is sitting out this competition, having only recently returned to competition after having a baby.
In a non-Olympic event, French sprinter Florent Manaudou was fastest in the 50 fly, with Hungarian veteran Laszlo Cseh second in 23.32.
Finals later were the men's and women's 400 free and the 4x100 free relays.
Andrew Dampf can be followed at www.twitter.com/asdampf