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HIGHLIGHTS OF THE DAY

That'll do it for our coverage of Olympic track and field on Day 15 of the 2012 Summer Olympics. Highlights of the day included:

• Jamaica broke its own world record in the men's 4x100-meter relay, running the race in 36.84 seconds. The United States won silver in 37.04, which would have tied the world record had Jamaica not broken it again.
• Mo Farah won the men's 5,000-meter run, completing the double after winning the 10,000 earlier in the Olympics.
• The American women's 4x400-meter team won gold, smashing the rest of the field.

Thanks for reading.

IAAF RULE 163.3A

Here it is:

"In all races run in lanes, each athlete shall keep within his allocated lane from start to finish. This shall also apply to any portion of a race run in lanes."

So a Canadian runner must have gone out of his lane.

CANADA'S BRONZE TAKEN AWAY

Canada, which finished in third place, has been disqualified. Trinidad and Tobago is now up to the bronze medal, after finishing fourth.

The official citation is IAAF Rule 163.3a. I'll get the exact text on that as soon as I can.

Michael Steele/Getty Images

WIN CONFIRMED

The result is now official: Jamaica has won the gold medal in the men's 4x100-meter relay, and it has broken a world record in the process.

It was hard to expect anything else. Once Usain Bolt took the handoff and the race was still even, there was no way Jamaica wasn't going to win, save for an injury or meteor strike. Ryan Bailey ran heroically, but there's only so much a man can do against a superman.

STILL NOT OFFICIAL

Apparently, Jamaica's win is still not official:

Taking forever to verify clean exchanges and confirm Jamaica as the winner.

— Michael C. Lewis (@MCLTribune) August 11, 2012

Mike Hewitt/Getty Images

THEY WON'T GIVE BOLT THE BATON

Usain Bolt wanted to keep the baton the Jamaican team used, but the officials wouldn't let him! He told the official he "needed" it, but the official said he had to take it back.

What else does he need it for? The Olympic track races are over...

RECORDS ALL AROUND

Jamaica, for the third major competition in a row, sets a new world record in the men's 4x100-meter dash. They ran it in 36.84 seconds, breaking their own record from the 2011 World Championships.

The United States set a national record, with 37.04 seconds, which is also the old world record time.

Clive Brunskill/Getty Images

BOLT BRINGS IT HOME

It was close throughout, but once Usain Bolt had the baton, this race was over. And they set ANOTHER NEW WORLD RECORD.

PREDICTION

As we get set to kick off, are there any predictions? I'm going to take Jamaica in this one.

I don't see them setting a new world record, though.

I will also make a bold call and say that the United States will finish the race.

MEN'S 4x100-METER RELAY LINEUPS

If you need a reminder (or don't want to scroll down to find the earlier tweet I posted here), here are the American and Jamaican lineups for the men's 4x100-meter relay:

UNITED STATES: Trell Kimmons, Justin Gatlin, Tyson Gay, Ryan Bailey

JAMAICA: Nesta Carter, Michael Frater, Yohan Blake, Usain Bolt

For Jamaica, it's more of the same, as it's the exact same lineup it had in 2011. The only way it could be stronger would be if Asafa Powell weren't injured; Powell anchored the 2008 victory.

For the United States, it's a little bit of a surprise to me to see Kimmons in there. I would have thought Darvis Patton would be involved, but he did botch the handoff in 2011 by clipping another athlete and falling.

Patton will still get a medal for the Americans, as he ran in the first round.

Video of the men's 4x100-meter relay at the 2011 World Championships.

AMERICAN MEDAL COUNT UPDATE

Courtesy of Christopher Clarey of The New York Times:

So with Barrett 2d in high jump & gold in 4-by-400, USA now has 28 T and field medals at #London2012. 29th likely in 4-by-100. Don't see 30

— Christopher Clarey (@christophclarey) August 11, 2012

Ian Walton/Getty Images

MEN'S 4x100-METER RELAY PREVIEW

The only event left on the track is the men's 4x100-meter relay. For Jamaica, it's a chance to reassert its dominance in the sprinting world. For the United States, it's an opportunity for redemption.

In 2008, the United States team dropped the baton in its semifinal match, ensuring it would not even be in the final, where Jamaica won and broke the Americans' world record in 37.10 seconds.

In 2011 at the World Championships, the Americans made it to the final but suffered the same fate. Jamaica won again—again breaking the world record, in 37.04 seconds.

What will happen in 2012? Can the United States reverse its legacy of recent failure? Or will the Jamaicans win again?

You're not going to want to miss this race. It starts at 4 p.m. ET.

BRIGETTA BARRETT WINS HIGH JUMP SILVER

When Russia's Svetlana Shkolina failed to clear the bar at 2.05 meters/6 feet, 8 3/4 inches in the women's high jump, American Brigetta Barrett was assured to win at least a silver medal. Shkolina, for certain, would finish with bronze.

Russia's Anna Chicherova, the defending world champion, cleared 6-8 3/4 on her second attempt, putting her in the driver's seat for gold. Barrett couldn't clear the bar on her third attempt, landing her with a silver medal and confirming Chicherova's gold.

Ronald Martinez/Getty Images

UNITED STATES EASILY WINS WOMEN'S 4x400

From Deedee Trotter to Sanya Richards-Ross, through Allyson Felix and Francena McCorory, this race was never in doubt. The United States blew out the rest of the field to win the women's 4x400-meter relay in 3 minutes, 16.87 seconds.

Russia finished second to win silver (3:20.23), and Jamaica finished third to win bronze (3:20.95).

The last remaining track race at London 2012 is the men's 4x100-meter relay, a much-anticipated showdown between the United States and Jamaica, going off at the top of the hour.

WOMEN'S 4x400 UNDER WAY

The gun has gone, and the race is off.

Alexander Hassenstein/Getty Images

WALCOTT WINS JAVELIN

Trinidad and Tobago's Keshorn Walcott, just 19 years old, has won the gold medal in men's javelin with a throw of 84.58 meters/277 feet, 6 inches. Ukraine's Oleksandr Pyatnytsya won silver, and Finland's Antti Ruuskanen won bronze.

MEN'S 4x100-METER RELAY LINEUPS SET

This tweet says it all:

In 40 minutes, 4x100 relay. Jamaica (Lane 6) will go Carter-Frater-Blake-Bolt. U.S. (Lane 7) has Kimmons-Gatlin-Gay-Bailey. #London2012

— NYT Olympics Live (@LondonLive) August 11, 2012

Stu Forster/Getty Images

MEDALISTS SET IN HIGH JUMP

The three remaining competitors in the women's high jump are Brigetta Barrett of the United States, defending world champion Anna Chicherova of Russia and fellow Russian Svetlana Shkolina.

They were the only three to clear 2.03 meters/6 feet, 8 inches, and now they are on to 2.05 meters/6-8 3/4.

ONE THROW LEFT IN JAVELIN

With just one toss remaining, Trinidad and Tobago's Keshorn Walcott is still in the lead in men's javelin. He will throw last, so if anybody beats his current best of 84.58 meters, he will have one final opportunity to win gold.

Ukraine's Oleksandr Pyatnytsya throws just before him, and he is in second place right now.

CHICHEROVA CLEARS 2.03 METERS

In the women's high jump, defending world champion Anna Chicherova has cleared the 2.03-meter/6-foot, 8-inch bar. The other three competitors remaining have yet to succeed.

Paul Gilham/Getty Images

WOMEN'S 4x400-METER RELAY PREVIEW

The women's 4x400-meter relay will get under way at 3:25 p.m. ET. The United States comes in with the fastest qualifying time, at 3 minutes, 22.09 seconds.

It has made a couple of lineup tweaks since that first round. The American lineup will be: Deedee Trotter, Allyson Felix, Francena McCorory and Sanya Richards-Ross. Trotter and McCorory are carryovers from the qualifying round.

The United States is the clear favorite to win gold, but it will face a stiff challenge from Russia.

BAR RAISED IN WOMEN'S HIGH JUMP

The bar has gone up again, this time to 2.00 meters/6 feet, 6 3/4 inches, in the women's high jump. American Chaunte Lowe has already failed on all three attempts at the height. She finishes the competition in sixth place.

American Brigetta Barrett is still going strong, making the mark on her second attempt. She is one of four athletes left.

Stu Forster/Getty Images

SAVINOVA WINS WOMEN'S 800 AGAIN

Russian Mariya Savinova defended her 2011 world championship to win the women's 800-meter run, finishing in 1 minute, 56.19 seconds.

American Alysia Johnson Montano set a blistering pace in the first lap, running it in 56.31 seconds, but she couldn't sustain her run in the second 400 meters. Kenya's Pamela Jelimo took over the lead shortly after the start of the bell lap, but Savinova surged past her at about the 600-meter mark to take gold.

South Africa's Caster Semenya ended up with silver (1:57.23), and Russian Ekaterina Poistogova won bronze (1:57.53). Jelimo ended in fourth (1:57.59), and Johnson Montano finished fifth (1:57.93).

WOMEN'S 800 SET TO GO

The runners are being introduced for the women's 800-meter run final. The gun is imminent.