A 21-year-old man died from cold water shock after accidentally falling into a river following a team-building day out, an inquest was told.

Sebastian Sailes vanished after he left The Black Horse pub in Chippenham, Wiltshire, on 27 February 2025. It was -5C (23F) that night and the ground was slippery near the River Avon where he walked, the inquest was told.

Following a huge search mission, including police divers and volunteers, his body was recovered from the river12 days later.

Coroner Grant Davies ruled that Sailes' death was a "tragic accident", adding the circumstances of how he entered the water remain unclear.

Speaking at Swindon and Wiltshire Coroners' Court on Tuesday, Harry Haynes, a pathologist at Great Western Hospital, said Sailes was likely to have suffered cold water shock when he entered the river.

Sailes, who lived in Notton near Lacock, was on an industrial placement at Holman Fleet Services' marketing department in Chippenham at the time of his death.

Along with his colleagues, Sailes attended a team-building day out in Bath before he returned to Chippenham on the train with his line manager Aidan Bartlett.

His colleague, Katie Davies, told the inquest that nobody seemed drunk.

At about 23:22 GMT, Sailes left the pub and texted Bartlett saying, "walking back, carry on your night".

Bartlett told the inquest: "I went down to try to find him.

"I sat on the Town Bridge, it allows you to see up both sides of the town. I sat there for an hour and tried to call him."

Sailes' girlfriend, Jess Noble, described him as a "ray of sunshine".

She told the inquest: "We were in the process of putting a deposit down for our university house. He was the happiest guy I knew."

His father, Blair Sailes, said that his son loved sports, including cricket and rugby, and had "an amazing life ahead of him".

The coroner said the "fatal synergy" of the water immersion and alcohol levels contributed to Seb's death.

Coroner Davies said: "Sebastian was recovered from the River Avon adjacent to Westmead Open space in Chippenham, Wiltshire.

"The precise circumstances of which Sebastian came to be in the water remain unclear.

"But Sebastian had unintentionally fallen into the River Avon at some point after 23.24 on 27 February 2025."

As to how Sailes entered the water, Davies said: "Sadly, we'll just never know. But I do not think it was intentional."

Follow BBC Wiltshire on Facebook, X and Instagram. Send your story ideas to us on email or via WhatsApp on 0800 313 4630.