Per USA Today and ABC also, IIRC, Busch was coughing up blood the day before, when he collapsed:
https://www.usatoday.com/story/sports/nascar/2026/05/22/kyle-busch-death-911-call/90216846007/
Underestimating a lung problem has killed a lot of people. That got one of my brothers.
This is what we’re hearing now. Kurt and Samantha will likely be doing ads for lung awareness. Too much carbon monoxide poisoning from 30 years of racing from Bandolero to Cup.
Busch’s first four seasons of national series racing (2001, 2004-06 plus 2007 Daytona 500) were the last seasons with leaded racing gasoline. There has also been use of leaded racing gasoline in Super Late Models. If enough lead poisoning is found in his lungs, there will be a call by NASCAR and many local racing officials to switch to unleaded racing gasoline at short tracks.
NHRA Pro Stock team owner Eric Latino’s Global Emissions Systems Inc. (GESI) has been testing catalytic converters and unleaded gasoline for NHRA Pro Stock with his KB Titan team he co-owns with a consortium. NASCAR already mandates mufflers at some races to improve driver safety.
In 2024, Latino (when the NHRA was with Sunoco), experimented with Sunoco’s unleaded racing fuel used by NASCAR from 2007 to 2010 (260 GTX).
Greg Anderson tested Latino’s GESI Camaro with catalytic converter, noticing it lost no power.
Do not be surprised to see Eric Latino and NASCAR test a GESI catalytic converter and muffler on a Cup car later this year potentially for 2027 with new rules in other Late Model classes to ban leaded gasoline. Leaded gasoline is being phased out of aircraft by VP Racing Fuels (NHRA provider) and LyondellBasell, which is developing unleaded Avgas.
https://competitionplus.com/catalytic-converters-on-a-pro-stocker/
I read he died from walking pneumonia in both lungs.