Valtteri Bottas goes quicker than Hamilton too, and up to second. But Raikkonen is flying again...

1) RAI 1:27.199

2) BOT +0.165

3) HAM +0.243

4) VET +0.652

5) LEC +1.563

6) ERI +1.629

It's quick from Raikkonen. It's very quick. A time of 1:27.199 takes him above Lewis Hamilton, and back to the top of the leaderboard by 0.243 seconds. Expect the Mercedes drivers to respond in the 13 minutes that remain...

Image source, Reuters

Carlos Sainz is told there is debris at Turns 12 and 13 - both high speed corners, so not ideal. It's nothing that seems to be troubling the race officials that much, though. Stoffel Vandoorne, meanwhile, is complaining that he has zero rear grip.

And Kimi Raikkonen is out on new soft tyres to build up some speed...

Renault tell Jennie Gow that Hulkenberg came in because he was unhappy with the way the car was performing. Which is odd, because it definitely didn't sound as if he was the one initiating the pit stop.

Nico Hulkenberg gets a message from the Renault team radio. "We need to box this lap," he is told.

"Why?" he asked.

"There's an issue that we need to sort out," comes the reply. Whatever the problem is, they don't want everyone else knowing about it.

Image source, Getty Images

Lewis Hamilton, picking up speed, goes faster that Kimi Raikkonen with a time of 1:27.442, and jumps to the top of the standings.

Jennie Gow
BBC Radio 5 live pit-lane reporter

Brendon Hartley has been sent to the medical centre for checks. The medical delegate says it looks OK but if you have an impact above a certain G-level, you have to go for checks, and that's what's happened. Toro Rosso are doing work on the front left of the car. They're not sending out Pierre Gasly until they're 100% sure that there's not going to be a problem with him as well.

Image source, Formula 1 Twitter

1) RAI 1:27.607

2) HAM +0.094

3) VET +0.244

4) BOT +0.674

5) VER +1.462

6) MAG +1.989

Pierre Gasly is taking off his overalls - Toro Rosso are taking no chances in sending out their other driver after Brendon Hartley's horrible accident.

Image source, EPA

But Hamilton is just slightly slower overall - 1:27.701, which is 0.094 seconds down on Raikkonen.

Image source, Reuters

Lewis Hamilton out on a flying lap - and faster than Kimi Raikkonen through the first sector...

Image source, Reuters

With so much time lost, everyone will be desperate to get some fast laps in - and so we've got just about everyone out there now.

The session restarts with 33 minutes to go.

Jennie Gow
BBC Radio 5 live pit-lane reporter

The Toro Rosso investigation still continues. They're just watching the impact and the lead up the incident. They have their own servers so they can watch it in their own time. A lot of mechanics going past me to try to recover Brendon Hartley's car, so they can investigate it. If Hartley gets out for qualifying this afternoon, I would be incredibly surprised.

Image source, Formula 1 Twitter

"Let me know if he's OK," says Sebastian Vettel over his team radio, having gone past the scene of Hartley's crash.

"Yeah, he's OK," the Ferrari radio responds in reassurance.

Jennie Gow
BBC Radio 5 live pit-lane reporter

I did see Brendon Hartley this morning and he's such a likable guy, probably one of the nicest guys competing in F1. He's safe in the Toro Rosso seat until the end of the year but when things like this happen, does it undermine your confidence? If you're in a championship and do well, and come to F1 and it just doesn't click, that must be a horrible sensation to go through.

Image source, Getty Images

Rachel T: Good grief, horrible suspension failure for Hartley. So glad he is OK.

Jeremiah Kariuki: Very strange how that car of Brendan Hartley broke and destroyed the front wheel. Could be the bumps that some drivers have been complaining about. Very lucky for Hartley he is fine.

Applause for Brendon Hartley as he walks to the medical car - just to be checked over as a precuation, by the looks of it. He was propelled into the gravel at great speed as his suspension failed there - a huge plume of dust went up. The front wheels are dangling off the car as it is lifted away.

Image source, Formula 1 Twitter

Red flagpublished at 11:16 BST 7 July 2018

11:16 BST 7 July 2018

Brendan Hartley goes into the barriers coming into Brooklands... He confirms on his radio that it's a suspension failure. We're going to have to stop for a bit. It's a nasty one - but he's OK, thank goodness.

Image source, Formula 1 Twitter