Firestone has confirmed to Motorsport.com that a cut tire was the cause of Josef Newgarden's airborne accident.
Sebastian Bourdais spent a lot of time in the grass at Barber today, but still found his way to second on the day.
The same tires were available at previous street course races.
Firestone Brand To Exit INDYCAR After 2011 Season
Firestone To Exit Indycar Racing After 2011 Season