A local artist has marked the spot where Shaun died with this memorial.
In the second of four articles examining the anatomy of a fatal road crash, Adrian Brown looks at how police, paramedics and other critical services responded in the moments immediately after one road collision.
At 7.41pm, a 999 call was received at Ambulance control in Kempston. The call was immediately relayed to Hertfordshire police headquarters in Welwyn Garden City who contacted all police units in the area.
Sgt Toni Hall was out on patrol in Stevenage when the "immediate" call came in. "I responded, saying that I was available, put my blue lights on and made my way to the scene," she says.
Others also heard the call. Traffic police officer Pc Vicki Richards was in another patrol car.
"It was a horrible night, January, and it was raining. The roads were very greasy", she remembers. She and her police partner turned their car in the direction of the incident and sped off, sirens blaring.
A paramedic fast response car was also dispatched from Stevenage ambulance station.
Sgt Hall was the first police officer to arrive. A crowd had gathered, illuminated, she recalls, by the street lights. Traffic was backing up but the road was still open.
"The first thing I did was to partially block the road with my car, I then ran up the road towards the crash. I shouted at a member of the public to move his vehicle to block the road on the other side.
"When I got to Mr Henderson I could see he was severely injured, there was a lot of blood. A nurse who happened to be in a car just behind the accident was giving him heart resuscitation." She felt for his pulse but couldn't find one.
1. 7.30pm: Shaun leaves home (approximate time)
2. 7.41pm: First 999 call made from crash site. Pc Hall arrives within minutes
3. 7.42pm: Paramedic leaves for crash scene, followed by ambulance
4. 2031: Van driver tests positive for alcohol in intoxicator room
5. 8.06pm: Shaun arrives at Lister, declared dead at 8.20pm
Four minutes (7.45pm) after the 999 call first came in, the paramedic arrived.
"The bike was on top of Mr Henderson, so we had to lift it off, to get him out and ready for the ambulance," Pc Hall remembers. Someone mentioned to her that the driver of the van had been drinking.
"He'd parked his van by the side of the road. I shouted at the guy to get in his vehicle and stay there," she recalls.
Soon, others from the police and emergency services were arriving at the scene. Another member of the ambulance service, Communications manager Gary Sanderson, came from his home nearby after taking a call out. He called in two ambulances and helped get Shaun ready to be taken to hospital.
Three miles away at the Lister Hospital, A&E consultant Carolyn Meredith was coming to the end of her shift when the "red call" alerting her of Shaun's imminent arrival came in. There are four or five of these calls on any typical day, around a quarter of them for traffic crashes.
"We quickly assembled a trauma team - an anaesthetist, general surgeon, an orthopaedic surgeon, two registrars, and three nurses. I briefed them on what we knew, which was that we had a patient with serious head injuries."
On Six Hills Way, it was still drizzling as police officers closed the road and secured the area. The ambulance had arrived and Shaun was loaded into the back.
Shaun was rushed to Stevenage's Lister Hospital
"The casualty was rapidly treated, put on a spinal board and taken to the Lister. You do your quick stabilisation at the scene and then get them to hospital as soon as you can," Mr Sanderson explains.
Ten minutes after the paramedic arrived, traffic officer Pc Richards' patrol car pulled up at the crash scene. Every serious road crash has an investigating officer assigned to it, and this one was to be hers.
After a quick brief from a colleague on the scene, she made "a bee-line" for the van driver.
Her memory of their first encounter is very clear. "He was with another officer sitting in a police car. I remember getting into the car and immediately smelling alcohol. The driver was very quiet, very shocked."
As she talked to the driver, the ambulance left with Shaun on board. On the way to hospital, the ambulance crew reported that Shaun's heart had stopped.
By now, other police officers were on their way.
Twelve miles away at Hertfordshire police headquarters, collision investigator, Pc Roy Ward, was working in the Road Death Investigation Unit, a drab, blue temporary building sitting on the edge of a windswept car park.
"I was in the office doing paperwork. I took the call on the 24-hour phone. I left immediately in one of the two special vehicles we have on constant standby.
The accident investigation unit has two MPVs
They're fitted out with specialist equipment, including digital cameras, special road markers, and a decelerometer that measures road friction
They also carry a surveyor's theodolite for measuring road layout.
Before Shaun reached hospital, Pc Richards had breathalysed the van driver who'd given a positive breath test. She arrested him for driving while over the limit, and took him off to Stevenage police station together with Sgt Hall.
As Pc Richards arrived at the station, she spotted the custody sergeant and called out: "He's blown 48 and someone's dead", signalling that she wanted the driver booked in rapidly so that a second, more accurate, reading could be taken.
"I knew we had a gentleman who was seriously injured if not already dead and a man who's failed a breath test. The evidence is in the body and we're potentially losing it the longer we delay," she explains.
It was six minutes past eight, when the ambulance carrying Shaun arrived at the Lister and he was quickly brought into the resuscitation bay. Dr Meredith's team gathered around Shaun who was being kept alive by cardiopulmonary resuscitation (CPR).
"We kept CPR going while we examined Mr Henderson, checking his airways, breathing and circulation. There were no reversible causes for his cardiac arrest that we could treat because sadly, brain and spinal injuries that are enough to stop your heart are usually always overwhelming and unfortunately, this was the case here," Dr Meredith recalls.
"The brain stem and spinal cord are responsible for keeping your heart beating. If you damage these structures seriously enough, your heart stops and that is likely to be what happened with Mr Henderson."
Shaun was declared dead at 8.20pm.