Andrew Benson
BBC F1 correspondent in Austin

He went in overambitious into the first corner, Yuki Tsunoda. Was it a Racing Bulls he hit? Lots of chaos going on. Hamilton's worried about the carbon fibre debris. All the headlines are going to be about McLaren but poor Fernando Alonso, he has not had luck this year.

Lewis Hamilton flags to his pit wall there is debris all over the track - and he's not wrong. Is there a Williams carrying damage out there, too? Hamilton has moved up to fifth as George Russell goes up to second and Carlos Sainz into third. Nico Hulkenberg has dropped all the way down to 15th place.

Andrew Benson
BBC F1 correspondent in Austin

Oscar Piastri got a better start than Lando Norris, we are seeing a McLaren stranded on the pit exit. It must be Lando Norris. Fernando Alonso also got caught in that incident. What happened was Piastri got a better start and he went around on the outside, then he tried to cut back on the inside and then the two McLaren and Nico Hulkenberg get in a tangle. Both McLarens are out of the sprint race.

That was a mess. Oscar Piastri was hit by Nico Hulkenberg and his car was sent up into the air and over to his team-mate Lando Norris. McLaren boss Zak Brown tells Sky Sports he hopes the damage is "relatively easy to fix". There was debris all over Turn One from the Sauber of Hulkenberg and the Aston Martin of Fernando Alonso, who was also caught up in that opening-lap collision.

Damon Hill
1996 world champion on BBC Radio 5 Sports Extra 2 in Austin

It was absolute carnage there, there were cars all over the place. I think, Max seems to be unscathed.

Max Verstappen has reached his grid spot at the front of the pack as the sun beats down on the Austin circuit. The last cars are making their way into position now. We're almost ready...

Jennie Gow
F1 pit-lane reporter in Austin

33C, some of the drivers are wearing their cooling vests, it's going to be a real battle for them to stay cool. Not as hot as Singapore, but it is hot and it's windy, with the wind going from right to left. It's going to be a real threat.

Max Verstappen is on sprint pole in Austin for the third year in a row but can the Dutchman make it three consecutive wins at the Circuit of the Americas?

The two McLarens of Lando Norris and Oscar Piastri are starting just behind Verstappen, so can they knock the four-time world champion off his sprint throne?

All the drivers have opted for the medium compound for this 19-lap mini race.

Damon Hill
1996 world champion on BBC Radio 5 Sports Extra 2 in Austin

Every point always matters, world championships have been lost by half a point and quite often it comes down to a critical last race. I just think the sprint, the drive is less attacking. [The drivers] behave themselves more in this format.

Image source, Getty Images

Red Bull's Max Verstappen, who starts on sprint pole, speaking to Sky Sports: "Always difficult to say [if he knew he could get the car on pole].

"I think in SQ1 and SQ2 we weren't too bad, quite close and in SQ3 it was about getting your references right as you only have one attempt so it's quite tough.

"It was good, the lap was good. I expect it to be a proper battle now in the race with McLaren. It's a bit warmer but it is the same for everyone."

BBC Radio 5 Sports Extra

Jennie Gow, Harry Benjamin and Andrew Benson are joined by 1996 F1 world champion Damon Hill for the rest of the weekend.

The team are in position now for the sprint, so click the 'listen live' tab at the top of the page to tune in to Sports Extra commentary.

Ian Fergusson
BBC weather forecaster

Image source, Getty Images

Air temperature is 29.4C, track 42.8C; humidity ~60%. Dry/fine.

Wind mostly from south-south-west; gusts to 22mph in past hour. FIA official risk of rain is 0%.

Sunday a little cooler (max 29-30C) and also expected dry.

Image source, Getty Images

If this is your first time for a sprint event, welcome in!

The 100km race is the first track action on Saturday. Qualifying for the main grand prix takes place later on.

The grid was set during yesterday's sprint qualifying session and the race will be run over 19 laps of the Circuit of the Americas, with drivers free to choose whatever tyre compound they wish. Pirelli has brought along the C1 as the hard, C3 as the medium and the C4 as the soft.

The top eight finishers score points, from eight for first place to one for eighth spot, which will get added to the overall drivers' championship standings.

Here are the drivers are who starting in those points places:

1. Max Verstappen (Red Bull)

2. Lando Norris (McLaren)

3. Oscar Piastri (McLaren)

4. Nico Hulkenberg (Sauber)

5. George Russell (Mercedes)

6. Fernando Alonso (Aston Martin)

7. Carlos Sainz (Williams)

8. Lewis Hamilton (Ferrari)

5 Live F1 commentator Harry Benjamin is in Austin and has put together his list of five things we should watch out for this weekend at the United States Grand Prix. Have a look below.

McLaren already have the constructors' crown secured, so which team will finish runners-up this season? Mercedes hold that spot now and are 27 points clear of third-placed Ferrari and 35 points ahead of Red Bull in fourth, who can cut the deficit to the Scuderia today with a win in the sprint.

Image source, Getty Images

Image source, Getty Images

The gap between title leader Oscar Piastri and second-placed Lando Norris is 22 points heading into the fourth sprint event, so every point counts in the race to become F1 world champion by Abu Dhabi in early December. Norris has the edge over his Australian team-mate in Austin today by starting one placer higher on the grid.

For Max Verstappen, the hope of a fifth consecutive title is still mathematically possible, but the Dutchman is 63 points off Piastri with six races and three sprints remaining.

Nico Hulkenberg's P4, meanwhile, puts him in a great position to overtake Isack Hadjar in the standings if he can keep the quicker cars at bay and finish in the top six.

Image source, Getty Images

Oscar Piastri and Lando Norris aren't starting alongside each other today - Norris is next to polesitter Max Verstappen and Piastri is lining up with Nico Hulkenberg - but how will the two drivers approach Austin's mini race after last week's drama in Singapore, and with one eye on the championship?

On Thursday, Norris said he will face "consequences" for the first-lap contact with his team-mate, but McLaren are staying tight-lipped as to what the repercussions are - "nothing draconian" was boss Zak Brown reply yesterday.

Will it affect how either of them go racing? Or will we see a good, clean scrap between the pair in the sprint?

After missing out on pole, Norris said it wasn't a surprise for McLaren "to be just a bit slower than the Red Bull lately", while Piastri called his lap "scruffy", adding: "In some ways, I feel a bit fortunate to be third."

Image source, Getty Images

Max Verstappen claimed his 10th career sprint pole position with the last lap of the session in SQ3 on Friday, pushing Lando Norris down into second place with a time of 1:32.143.

The Dutchman has dominated this shorter format since it was introduced in the 2021 and has taken victory in 12 races. For context, Valtteri Bottas, Oscar Piastri and Lando Norris are next on the list with two wins each.

Verstappen said after qualifying he expects a tough battle in the sprint today and added: "But that's exactly what we want to see, right?" Right.

Lorraine McKenna
BBC Sport Journalist

Image source, Getty Images

Hello, folks. The fourth of six sprint events this season is upon us and it's the resurgent Max Verstappen who starts on pole position ahead of the McLarens of Lando Norris and championship leader Oscar Piastri. The Dutchman has been picking off the two papaya drivers of late and is tentatively being added back into the title mix.

The sprint race in Austin, which is 19 laps of COTA, starts at 18:00 BST.

Behind the front three, Nico Hulkenberg took an excellent fourth in sprint qualifying yesterday, while Ferrari had another session to forget. Charles Leclerc, who starts outside the points in 10th, said the Italian team are "so far behind" their rivals.

As for the weather in Texas, it's another hot one, with temperatures reaching a high of 34C across Saturday's track action.