The Metropolitan Police has confirmed a second death following a late-night collision in Southgate, after a 31-year-old man died in hospital more than a week after the crash.
Patrick Cassidy, 31, had been taken to hospital with serious injuries after the collision on Chase Side, Southgate, at around 00:40 on Saturday 20 September, when a car was involved in a collision with a pedestrian. He died on Wednesday 30 September.
His death comes just eight days after William Cassidy, 48, who was rushed to hospital in a critical condition from the same crash, died on Tuesday 22 September.
Emergency crews raced to Chase Side
Officers were called to Chase Side in the early hours of Saturday 20 September after reports of a road traffic collision involving a car and a pedestrian. They attended alongside paramedics from the London Ambulance Service, crews from the London Fire Brigade and a trauma team from London’s Air Ambulance.
Several people were taken to hospital for assessment. Alongside the two men who later died, three other passengers in the vehicle — a man in his twenties and two women in their thirties — were taken to hospital. Their injuries have been assessed as neither life-threatening nor life-changing.
The pedestrian, a man in his thirties, was also taken to hospital. His injuries have likewise been assessed as neither life-threatening nor life-changing.
Woman arrested and released on bail
A 32-year-old woman was arrested on Monday 21 September on suspicion of causing serious injury by dangerous driving and of driving with a specified controlled drug above the prescribed limit.
She was further arrested while in custody on suspicion of failing to stop, and has since been released on bail while enquiries continue. The Met has confirmed she is not related to any of the vehicle’s occupants.
“Any information you have could be vital”
Detective Inspector Simon Ager, of the Met’s Serious Collision Investigation Unit, said the collision had now claimed two lives and that his team’s thoughts remained with the men’s loved ones.
He said officers were working hard to establish the full circumstances and urged anyone who witnessed the incident to come forward. “Any information you have could be vital in our investigation,” he said, asking anyone who was in the area at the time — or who may have captured CCTV, doorbell or dashcam footage — to get in touch, as the material could prove crucial.
Detectives have issued similar witness appeals in other recent cases, including after a 68-year-old man died in a van collision in Southall.
What happens next
The investigation remains live, with the arrested woman on bail while detectives continue their enquiries. In fatal collision cases, specialist officers typically piece together the movements of those involved, examine forensic evidence recovered from the scene and review any available footage before a file is prepared for the coroner and, where appropriate, prosecutors.
Timeline: key events
- Saturday 20 September, around 00:40 — police are called to a collision between a car and a pedestrian on Chase Side, Southgate.
- Monday 21 September — a 32-year-old woman is arrested on suspicion of causing serious injury by dangerous driving and drug-driving; she is further arrested for failing to stop.
- Tuesday 22 September — William Cassidy, 48, dies in hospital.
- Wednesday 30 September — Patrick Cassidy, 31, dies in hospital.
- Monday 5 October — the Met confirms the second death and renews its appeal for witnesses and footage.
Difficult period on north London’s roads
The Southgate deaths come during a difficult spell on the capital’s roads. Last week, a 17-year-old boy was killed in an Enfield e-bike crash, with a 60-year-old driver arrested on suspicion of dangerous driving.
Elsewhere, a man has been charged with causing death by dangerous driving after a fatal collision in Southall, while a man died following a collision on Curnick’s Lane in West Norwood last month.
Can you help?
Anyone with information is asked to contact police on 101, quoting reference 259/20SEP. Alternatively, you can contact the independent charity Crimestoppers anonymously on 0800 555 111 or via its website.

