The New Jersey highway patrol confirms Leffler died at 9:02 pm Eastern, after a crash in a sprint car heat race. Reports from the track say he was cut from his car and flown to a nearby hospital, where he died from his injuries.
Leffler most recently drove the No. 19 Humphrey Smith Motorsports car in the Sprint Cup series. He had his most success in the Nationwide series, where he finished third in the points standings in 2007. He had two nationwide wins and 107 top ten finishes.
He made his name coming up in the spint car ranks, winning USAC National Midget championships in 1997, 1998, 1999 and the USAC Silver Crown championship in 1998. He also ran one Indianapolis 500, finishing 17th.
Leffler was 37 years old. He is survived by his 5 year old son, Charlie Dean.
As news of Leffler's death became official, fellow drivers began tweeting their condolences.
@ClintBowyer: So sad to hear about @JasonLeffler. Was a wheel man and a fun fun person to be around.
Sitting here in disbelief.. All I can think about is Charlie.. Prayers to the Lefler family...
@JasonLeffler was a hard racer. He loved to race and will be missed. Please keep his family in your prayers
@keselowski : Really sad for Jason Leffler and his family. Thinking about his little boy...
Extremely sad to hear about @JasonLeffler spent a lot of time racing with him. Gone way too soon. Prayers to his entire family.
@: Another racer gone too soon. So sad, Our thoughts are with his family and friends.
NASCAR released the following statement about Leffler's death: “NASCAR extends its thoughts, prayers and deepest sympathies to the family of Jason Leffler who passed away earlier this evening. For more than a decade, Jason was a fierce competitor in our sport and he will be missed.”