A troubled week for the Verizon IndyCar Series just got even worse, with Schmidt Peterson Motorsport's James Hinchcliffe injured in a big impact in turn 3 during the final day of practice for the 99th running of the Indianapolis 500.

Just under an hour into the day's session, the number #5 car appeared to suffer some sort of mechanical failure as it came through the turn and went straight into the wall at full speed. Despite the presence of a SAFER barrier, the car suffered major right side damage and also caught fire, while a tyre came detached and was narrowly missed by Sebastian Saavedra.

As the car slid down to the apron it came close to toppling over on the right hand side, before finally coming to rest right side up. Witnesses said that it did not seem to be the same sort of airborne incident that had previously afflicted Helio Castroneves, Josef Newgarden and Ed Carpenter, none of whom suffered significant injuries or required a trip to the hospital as a result.

Ed Carpenter's accident on Sunday led to a raft of emergency rule changes for qualifying while IndyCar investigated whether there was something with the new aero kit designs that might be contributing to an instability with the cars. At that point all three cars to have been flipped over were running Chevrolet components, but Hinchcliffe's aerodynamic components are provided by rival manufacturers Honda.

The only other Honda to crash at Indianapolis Motor Speedway this week was the Dale Coyne Racing entry driven by Pippa Mann which spun exiting turn 4 and hit the wall at pit entry. Despite significant damage to the #63 car, Mann herself was uninjured.

Hinchcliffe was described as awake and alert when the safety teams reached the wreckage of the car. However, he was not able to climb out of the car on his own, and once the safety team extracted him he was immediately placed on a stretcher and taken away by ambulance and transported by ground to IU Health Methodist Hospital in Indianapolis.

IndyCar medical director Dr Michael Olinger later reported that Hinchcliffe had undergone surgery for an upper left thigh injury. He has since been transferred to the Intensive Care Unit and remains in stable condition. Further medical updates will follow in due course.

"Obviously we're relieved that James is awake and out of surgery," said Schmidt Peterson Motorsports team owner Sam Schmidt. "That's the most important thing on our minds right now and we will do absolutely everything required to ensure a complete recovery."

Hinchcliffe had yesterday qualified for next Sunday's race in 24th place, and had set the ninth fastest time of 223.916mph during the Monday session before the crash occurred. The popular Canadian driver nearly missed last year's race after suffering a concussion from flying debris during the preceding event in 2014, the inaugural Grand Prix of Indianapolis in the new in-field road course at Indianapolis Motor Speedway.

The Monday practice session was stopped after Hinchcliffe's crash, partly to allow repairs to the turn 3 barrier before the Indy Lights cars were allowed to resume their own preparations for Friday's Freedom 100 event. Series officials said they wanted the opportunity for chassis manufacturers Dallara to look into potential causes of Hinchcliffe's accident before allowing the IndyCar teams to venture back out again. Honda eventually confirmed that it appeared to be the result of a failure of the right-front suspension rocker arm.

Before Hinchcliffe's accident, Penske's Simon Pagenaud had topped the timesheets with a lap of 225.260mph (39.9538s), seven thousandths of a second ahead of Justin Wilson in the #25 Andretti Autosport Honda. Only 24 of the 33 Indy 500 entries had managed to get out on track and set a time before the session was curtailed.

IndyCar practice did eventually resume at 4.15pm local time and went on until 6pm. In a busy session largely dedicated to race simulation runs, Chip Ganassi Racing's Sage Karam ending up on top of the times with an impressive best effort of 39.5029s (227.831mph) putting him 0.2249s ahead of team mate Scott Dixon who 24 hours earlier had won pole position for the Indy 500. JR Hildebrand continued to impress with the third-fastest time of the late afternoon session.

James Davison returned to action with a best lap of 226.109mph to finish fourth fastest after missing qualifying because of a conflicting motorsport engagement in Mosport, Canada. The Dale Coyne Racing #19 had been qualified in 21st position on the grid by Tristan Vautier in his absence. Pagenaud improved his time marginally on the earlier session to 225.794mph but that was only good enough for sixth place this time around.

28 drivers took part in the session, which was incident free save for an engine expiration for the #41 AJ Foyt Racing car driven by Jack Hawksworth. As well as Hinchcliffe, also absent from the session were his team mates James Jakes and Conor Daly as SPM took stock of the afternoon's events and awaited word on Hinchcliffe's condition and what it might mean for their race weekend. Carlos Huertas and Oriol Servia also sat out the session.

Hinchcliffe is in his first season with SPM after moving from Andretti Autosport over the off-season. The 28-year-old won the inaugural Indy Grand Prix of Louisiana on April 12 and also finished seventh in the Honda Indy Grand Prix of Alabama at Barber Motorsports Park on April 26.) In 73 starts covering five Verizon IndyCar Series seasons, Hinchcliffe has four victories and 19 top-five finishes. In four Indianapolis 500 starts, he has a best finish of sixth in 2012 an started the race from second place in 2014.

Trackside reporting by Lynne Huntting of PressSnoop.com.

Full times from practice 9 for the Indianapolis 500.Full times from practice 10 for the Indianapolis 500.