Kyle Busch's grieving wife Samantha attended the Coca-Cola 600 with their two young children on Sunday just three days after the NASCAR legend's sudden death. 

Busch, a two-time Cup Series champion and father of two, died of complications after suffering with 'severe pneumonia that progressed into sepsis' on Thursday, shortly after being hospitalized. He was 41. 

In the wake of the heartbreaking news, NASCAR held a moment of silence for the iconic driver ahead of the Coca-Cola 600 - the first race since his tragic passing. 

In an incredible display of strength, Busch's heartbroken wife Samantha attended the race, clutching a bouquet of white roses as she joined the emotional tribute to her late husband. 

Busch, who competed in more than 760 races during a storied 24-year career, is survived by Samantha, and their two children, Brexton, 11, and Lennix, four.  

Samantha struggled to keep her composure, breaking down into tears as she and son Brexton stood arm-in-arm on the track. 

As three pipers played a somber rendition of Amazing Grace, Samantha was handed her young daughter Lennix by a member of the mourners gathered at the Charlotte Motor Speedway. 

Samantha cradled the youngster, who sported black-and-white checkered bows in her hair in a touching nod to her father's legacy. She then huddled her two children together as her body was wracked with sobs. 

Brexton sported a black cap with his father's No. 8 embroidered on the front - a number that has now been temporarily retired until the 11-year-old follows in his father's footsteps and one day races in NASCAR. 

Both he and his mother wore black t-shirts with a logo emblazoned on the front that read: 'Battle of the Busches.' 

The Battle of the Busches was a series of dirt track races between Kyle and his racing-phenom son, which began in March of last year.  

Busch's parents, Tom and Gaye, and his brother, NASCAR Hall of Famer Kurt Busch, also attended the race as NASCAR honored the late driver with a moment of silence. 

Kurt, a NASCAR champion himself, laid a bouquet of white roses on a No 8, which had been stenciled onto the infield grass in black paint in remembrance of his younger brother. 

NASCAR CEO Steve O'Donnell shared some heartfelt words as the series honored Busch. 

'No one ever feels fully prepared to speak at a moment like this and I think we can all agree this was Kyle Busch's home,' he said.

'Every race track was Kyle Busch's home. He competed like he had something to prove every single race, when in reality he'd already proven everything. 

'What I think we'll miss most isn't the wins. It's the guy who quietly wanted to help a teammate or give some advice.

'It was the husband, the father, or the guy who quietly did things for others when no one was watching. And to the Busch family - Tom, Gaye, Kurt, all the folks at RCR and JGR, we are certainly thinking about you.'

He added: 'Samantha, I want you to know that this sport stands with you. And you and your children are NASCAR family forever.'

'And Brexton and Lennix, your dad loved you with all his heart. Everyone gathered here, everyone behind, you, everyone watching on TV and all those people up in that grandstand are your family, and we've got you.'

The tributes to Busch continued following the emotionally-charged tribute as the US Army Golden Knights carried Busch’s flag prior during pre-race festivities. 

Each of the 39 cars in field also carried Busch's decal, while on the pace lap, they formed the missing man formation.

The speedway’s public address system and the television commentators went silent on the eighth lap of the race.

Busch reportedly become unresponsive while using a racing simulator in Concord, North Carolina on Wednesday and was even seen coughing up blood, according to a 911 call released by TMZ.

He was hospitalized on Thursday before NASCAR announced his passing later that evening in a statement shared on behalf of his family.

Sepsis is considered a life-threatening medical emergency that occurs when the body has an extreme, overactive response to an infection, causing the immune system to damage its own tissues and organs, according to the Centers for Disease Control and Prevention .

Typically the immune system releases chemicals to fight off pathogens like bacteria, viruses or fungi, but with sepsis the response goes into overdrive. The results can cause widespread inflammation, form microscopic blood clots and make blood vessels leak.

It has since emerged that Busch was struggling with something in his final weeks.

He radioed for medical assistance from his car in the middle of one of his final NASCAR races on May 10 in upstate New York, just days before his death.

An eerie clip emerged from May 16 of Busch being asked if he had recovered from what he thought was simply a nasty cough.

'I had a pretty - you can kind of still hear it, I'm still not great,' Busch said, waving his hand to his face as he spoke to Jeff Gluck of The Athletic. 'But er, the cough was pretty substantial.'

In a clip from Busch's May 10 race, he was asking for a doctor to urgently meet him to give him 'a shot'.

With 38 laps to go in the NASCAR Cup Series game, Busch told his team over the radio: 'Can somebody try to find Bill Heisel? He's the kindred doctor guy. Tell him I need him after the race, please.'

He was then asked whether he needed the doctor at his car or his bus, to which he replied: 'Uh, bus. I'm going to need a shot.'

According to the TV broadcast, Busch had been struggling with a sinus cold that was exacerbated by the intense G-forces and elevation changes at the New York road course.

Busch went on to claim his record fifth NASCAR Craftsman Truck Series trophy that day, despite clearly still struggling with illness.

Following his death, which came just six days after the victory, a heartbreaking clip of Busch's post-race interview resurfaced.

After earning his 69th career Trucks Series race win with the triumph at Dover, Busch was asked how many races he wanted to win in his career before he stops racing.

'You take whatever you can get, man,' Busch said. 'You never know when the last one is going to be, so cherish them all - trust me.'