Justin Wilson critical, in a coma after head injury at Pocono (Updated)

IndyCar driver Justin Wilson suffered a severe head injury Sunday afternoon at Pocono Raceway when he was hit in the head by debris from Sage Karam's car after Karam crashed. As of 9 p.m. ET, the IndyCar Series said he's in a coma and in critical condition at an Allentown, Pennsylvania, hospital.

Wilson was airlifted from Pocono following the accident. Karam was leading when he crashed in front of the field. Wilson was hit in the head by the debris, apparently knocked unconscious, and his car then hit the inside wall.

The crash happened with 21 laps to go in the 500-mile race. Karam was taken to a local hospital for a right foot injury.

It looks like Wilson was hit in the helmet by the nose cone of Karam's car, which is a much heavier piece of bodywork than others. You can see in this slow-motion replay how high the debris shoots into the air after it hits Wilson and how his car suddenly veers to the left after the hit.

Please be aware that this is a video of someone suffering a possible serious head injury.

Wilson, 36, has driven in major American open-wheel racing since the 2004 season. He was driving a partial schedule in 2015 for Andretti Autosport. He has seven wins in CART and IndyCar. His most recent win was at Texas in 2012.

It's not the first time that a driver has been hit in the head with debris recently. James Hinchcliffe suffered a concussion when he was hit from flying parts at the 2014 Grand Prix of Indianapolis. Like Formula 1 cars, IndyCars do not have canopies above the drivers' heads. However, canopies in open-cockpit cars aren't unprecedented. The NHRA approved canopies for its Top Fuel dragsters in 2012.

Wilson's teammate, Ryan Hunter-Reay, won Sunday's race.

- - - - - - -

Nick Bromberg is the editor of From The Marbles on Yahoo Sports. Have a tip? Email him at nickbromberg@yahoo.com or follow him on Twitter!

Follow @NickBromberg