On a bright October morning nine paddleboarders entered the River Cleddau for an idyllic paddle through the Pembrokeshire town of Haverfordwest.
Just minutes later three were dead and a fourth fatally injured.
On Wednesday their tour leader, former police officer Nerys Bethan Lloyd, 39, from Port Talbot, was sentenced to 10-and-a-half years in prison for causing their deaths.
The judge criticised her "abysmal" approach to health and safety, while an earlier report by the Marine Accident Investigation Branch (MAIB) found the deaths were "tragic and avoidable".
So what went so badly wrong?
And in the three-and-a-half years since the deaths of Paul O'Dwyer, 42, Andrea Powell, 41, Morgan Rogers, 24, and Nicola Wheatley, 40, what has changed to prevent it happening again?
On the day of the tragedy – 30 October 2021 – the group were on a tour run by Lloyd's Salty Dog Co Ltd, based in Port Talbot.
Lloyd was leading the trip alongside her friend and neighbour Paul, a dad-of-three and Army veteran.
Also on the trip was Paul's wife and six paying participants, including Andrea, Nicola and Morgan.
Andrea was a dental hygienist and a mother-of-one, Nicola – a poisons information specialist and toxicologist – had two children and Morgan was an assistant supermarket manager and trainee firefighter.
All four who died were good swimmers.
The group had met up the previous afternoon, stayed overnight at a rented property in Tenby and headed into Haverfordwest that Saturday morning.
Lloyd had established her company in June 2020, initially to sell clothing online, but by May the following year the company began delivering stand-up paddleboard (SUP) rental and training at Aberavon Beach which led to commercial tours.
That fateful Saturday morning the group arrived in a van in Haverfordwest just before 08:00 BST.
Before parking up, Lloyd and Paul stopped off in the town centre to inspect the river.
By about 08:49 everyone from the group was afloat and they set off downriver heading for Burton Ferry, with Lloyd out in front and Paul at the back.
They passed through Haverfordwest town centre five minutes later, with one of the group playing music through a portable speaker.
Minutes later they approached the weir.
Lloyd instructed those close by to follow her and keep to the centre of the river.
At 08:56, kneeling on her SUP, Lloyd slid down the fish pass in the centre of the weir and was swept quickly downriver.
The next participant tried to copy her but was unable to align their SUP with the fish pass and was washed over its right hand side and swept downstream.
Within about a minute, the next six paddleboarders descended the weir.
Andrea was the third paddleboarder to descend, Nicola was the sixth and Morgan was the eighth.
Each of their SUPs pitched forward and they fell into the turbulent water at the foot of the weir.
While the rest of the group was washed clear and swept downstream, Andrea, Nicola and Morgan were sucked into the hydraulic jump, or spin, a recirculating flow similar to a washing machine.
