- Video report by ITV News Reporter Neil Connery
At least 17 people have been injured, some seriously, after a crash involving two cars at a 'cruise' event designed to raise money for bereaved families.
Spectators claimed at least one of the vehicles involved, a Nissan 350Z and a Toyota GT86, was travelling at up to 70mph in the moments before the crash on Monkswood Way at around 9.45pm on Thursday.
Organiser Rix Sidhu said it was the first time the Cruise-Herts group had suffered any serious incident in its 17-year history, with static meets often held in closed-off spaces where enthusiasts show off their modified vehicles.
Mr Sidhu said a small number of cars "went rogue" and left the car park, where crowds lined the main road to capture footage of the vehicles at speed.
He told ITV News the two cars involved were "not members of Cruise-Herts".
"We organised a charity meet to raise money for the charity 4Louis. We had our members walking round with buckets, collecting donations," he said.
He added club members were "devastated" by the incident.
"I've been running this for 10 years and we have never had one incident," he said.
"We held the meet in a car park with a speed bump at the entrance.
"But unfortunately some people went a bit rogue.
"We try and stop that, we urge people, urge them on social media beforehand, not to go out on the roads, not to risk injury or anything.
"But unfortunately, in this age of social media and Snapchat, people want to get footage and post things to their friends, which seems to drive some people to the main road."
Mr Sidhu said following Thursday's events, the club had made the "heavy decision" to stop their car meets.
"We don't want anyone else to experience anything like that. For me as a club owner, it was horrible, it was horrendous," he told ITV News.
Eye-witness Ciaran O'Conner said the people standing in the way of the cars "had no chance".
He told ITV News: "They had no chance of reacting, or moving out the way. It all happened so quickly."
Chief Inspector Alicia Shaw from Hertfordshire Constabulary said the police had not given permission for the event to take place, adding the force would be reviewing information and intelligence which would form part of the investigation."
She confirmed 17 people had been injured, two seriously.
The East of England Ambulance Service said it had taken 12 people to three hospitals – Lister Hospital in Stevenage, Watford General Hospital and The Princess Alexandra Hospital in Harlow.
An air ambulance also attended the incident.
An East of England Ambulance Service spokesman said: "There were a number of people in the area at the time and 16 people are presently being treated for injuries, some of which are serious."
Footage posted on Twitter shows a car trying to pass another vehicle at a junction before the two collide and plough into crowds.
One witness said on Twitter: “I’ve just witnessed that horrendous crash in #Stevenage, no more than 50ft away from me. I’m still trying to process it all.”
The meet was being help in aid of the 4Louis charity, an organisation which supports those affected by miscarriage, stillbirth and the death of a baby or child.
In July 2015, some 17 people were injured after a Ford Fiesta ploughed into a group of bystanders at a car cruise event in Plymouth, Devon.
A 19-year-old woman died and four others suffered life-changing injuries at an unofficial "car cruise" at Trafford Park, Manchester, in May 2018.
Scott Watkins, 25, was jailed in October for nine years and nine months after he caused the death of Sophie Smith by dangerous driving as he lost control of a high-performance vehicle and ploughed into a group of onlookers.
His BMW 3 Series, a friend's courtesy car, was one of more than 60 high-performance and modified vehicles said to have taken part at the unregulated event.