Heartbroken parents of missing Jack O'Sullivan retrace his last known walk every day: Graduate, 23, vanished last month after going to a party - as his desperate family say they have been trapped in 'hell' and are now living 'hour by hour'

The heartbroken parents of missing Jack O'Sullivan have said they retrace his last known walk every day in the hopes of finding something that might tell them what happened.

The 23-year-old law graduate vanished after going to a house party on Hotwell road in Bristol in the early hours of March 2.  

His mother Catherine O'Sullivan recalled how she woke up just after 5am that morning and 'instantaneously' knew 'something's wrong'. As she quickly realised her son was not home and using Find My Friends could see he was not at the location of the party. 

Her and her husband, Alan, immediately went out to search for him, in what would soon be the first of many days of 'hell'.

'We live hour by hour. You can't plan for the next day; we just communicate with police and we wait. We wait,' Ms O'Sullivan told the Telegraph.

Jack, who turned 23 on March 28, nearly a month after his disappearance was described by his mother as sporty, determined and gentle. 

She said: 'He put tremendous amount of effort into his next steps. He had already secured summer placements which are really hard to get. But he put in 45 applications.'

She added: 'Jack is a really good chap. He's very gentle. He just wanted to make sure everybody else was OK.'

He had gone to meet friends in Bristol for a usual Saturday night out, travelling by bus at 8.20pm from his village Flax Bourton to a Wetherspoons pub in the city. 

At 10.45pm he texted his mother that they had moved on to a house party and safely arrived at the new location. 

'All good, keys are safe,' he wrote. And at 1.52am he sent her a final text, saying he was OK. 

Then shortly before 3am Jack left the party alone, CCTV has captured part of his movement through the city, leaving the house party, crossing the Junction Swing Bridge and turning down Brunel Lock Road at about 3.15am.

He called a friend who was still at the party at 3.24am. When the friend returned the call ten minutes later, Jack answered the phone and said 'hello' but nothing else. The call lasted for 58 second before being disconnected. 

Ms O'Sullivan said the friend left the party soon after. 'She tried and tried to get hold of him but couldn't. She sent messages to him saying, 'please let me know where you are, please let me know you're OK' and 'please let me know when you get home'.' 

His family have now taken to walking his final route every day and at different times of the day just to try and experience what it might have been like for Jack, and any indication as to what could have happened. 

'I wanted to see if it was dark, and how it felt. But it's incredibly well-lit,' they said.

 Officers said his phone remained active on the Find My Friends app up until 6.44am.

Since then his parents have had to hear the heartbreaking news from the police that they are working on a hypothesis that he may have fallen into the river. 

They also approached the family with a key that was found by authorities that they thought might have belonged to Jack. But it was not his.   

Senior investigating officer DI Jason Chidgey said officers had used drones, dogs and dive teams in the River Avon as part of a 'significant number of searches' in the area.

Detectives have also carried out extensive CCTV trawls and house-to-house enquiries, as well as looking at Jack's phone to work out why that was active after his last confirmed sighting.

However, Det Insp Chidgey admitted his team was still trying to establish Jack's movements following the last sighting of him on CCTV.

He said: 'This is an incredibly difficult and distressing time for Jack's family and friends and we are continuing our efforts to try and find him.

'The smallest bit of information could make a huge difference in our investigation so, even if you don't think it is important, we encourage people to still get in touch with us.

'We are keeping an open mind about where Jack is but this is very out of character for him and we have been working hard to track his movements that night.'

Mr O'Sullivan is described as white, about 5ft 10ins (178cm) tall, of slim build and with short, brown hair.

He was last seen wearing a quilted green/brown Barbour jacket over a beige woollen jumper, navy chinos and brown leather trainers with white soles.