IndyCar driver Justin Wilson has died.

Wilson was hit in the head by a large piece of debris during yesterday's race at Pocono Raceway in Pennsylvania.

It's been confirmed he's passed away in hospital as a result of serious head injuries.

It's believed he was knocked unconscious at the time, instantly veering left and into the wall.

He was then airlifted to hospital where he was in a critical condition.

It's the second death in IndyCar in four years after Dan Wheldon was killed in 2011 after a big crash in Las Vegas.

He's survived by his wife Julia and daughters Jane and Jessica.

Wilson's younger brother Stefan, who is also an accomplished IndyCar driver, has said on Twitter that he can't begin to describe his loss.

Stefan Wilson said Justin was his brother, best friend, role model and mentor.

Wilson's team, Andretti Autosport, has released a statement.

It said Wilson was a tremendous racer, a valuable member of the team and respected representative of the sport.

They say his life and racing career is a story of class and passion surpassed by none.

The team said while Justin was only part of the Andretti lineup for a short time, it only took a second for him to forever become part of the Andretti family.