TONY KANAAN is leading after 100 laps. Seven cars are on the lead lap. There were five lead changes between polesitter HELIO CASTRONEVES, who didn't lead the first lap and Kanaan in the first 40 laps.

There were eight lead changes by the fifty lap mark. Other leaders include MARCO ANDRETTI, SCOTT DIXON, SAM HORNISH Jr and DARIO FRANCHITTI. Most of the passing occurred on track, not in the pits.

There have been four crashes, causing four cautions, and one incident in the pits. All were single car accidents. Two people have been transported to Methodist Hospital, one driver cleared to drive, and two pending but apparently alright. All drivers walked to the waiting ambulance.

ROBERTO MORENO hit the wall on lap 37. The car was damaged but he walked out of the car. He has since been transported to Methodist Hospital as he complained of pain in his upper back. Moreno was running 32nd at the time, one lap down. It brought out the second caution. The first caution was for track debris.

JON HERB hit the wall twice on lap 52. He is alright but his car was not and it brought out the third caution. He has been checked and released, 'cleared to drive.' An interesting phrase that. What would he drive?

DAN BROWN, right rear tyre changer on the car of AL UNSER Jr has also been transported to Methodist Hospital for X-rays on his left foot. No further details available at this point.

MILKA DUNO spun out and crashed several times rear end into the wall on lap 67, bringing out fourth caution. She walked to the ambulance. Duno had been running 31st, two laps down.

RYAN BRISCOE crashed the wall on lap 99. He bought out the fifth caution, but walked to the ambulance. Briscoe had been running twelfth, one lap down. His caution brought lead changes and a new leader on lap 101 - JEFF SIMMONS.

And now there's concern that weather is coming. Not good. The skies over the start-finish grandstands look threatening.