The families of three men and a teenage boy who died in an explosion at a water recycling centre in Avonmouth have paid tribute to them.
Luke Wheaton, 16, of Bradley Stoke, Ray White, 57, of Portishead, Brian Vickery, 63, of Clevedon, and Mike James, 64, of Bath, died in the incident at the Wessex Water site on December 3.
Avon and Somerset Police said the cordon around the site was removed on Tuesday evening, though work will continue at the scene as the investigation continues.
Luke's family described him as "the most gorgeous, loving, happy, talented, perfect son" and said he had "everything to look forward to in life".
"Luke knows how much he is loved and will be dearly missed by everyone. We just wish we could bring him back," they said.
He was a former pupil at Bradley Stoke Community School in Bristol and had recently started an apprenticeship at the plant.
Mr White's family described him as a "wonderful son, brother and father to his two sons" while Mr Vickery's family described how he "brightened everyone's lives with his cheeky and wicked sense of humour".
Mr James' family said he was a brother, husband, father and grandfather who would be missed.
The blast happened in a silo that held treated biosolids before they are recycled to land as an organic soil conditioner. One of the victims is said to have been thrown 150 metres (500ft) into a nearby lake.
It is understood that Mr James was a contractor working at the site, while Mr Vickery and Mr White were employees of Wessex Water. Luke was an apprentice at Wessex Water.
A fifth person who was injured in the explosion is now at home and investigators will speak to them when appropriate, said police.
An investigation into the cause of the explosion continues.
Giles Hyder, HSE's head of operations in the South West, said: "We send our deepest condolences to the families of those who tragically died. It is important a joint investigation is carried out.
"We will provide specialist support to what is likely to be a complex investigation under the command of the police."
Colin Skellett, chief executive of Wessex Water, said: "We are all absolutely devastated by what has happened.
"Our hearts go out to the family, friends and colleagues of those who lost their lives during the tragic event on Thursday.
"I know from the thoughts and comments I have received from so many, that this has affected the whole Wessex Water family.
"I know Avonmouth, I worked there for many years, and I know the people, some of whom have lost their lives during this terrible incident."
Mr Vickery worked at Wessex Water for 42 years and was nearing retirement, his distraught wife said.
Speaking on Friday, Ms Vickery said her son also works at the water recycling plant and only narrowly escaped being caught up in the blast as he was off on the day it happened.
"If he had been there he'd be dead too. We didn't hear anything for about five hours after it happened," she said.
Bristol City Mayor Marvin Rees was among those who paid their condolences to the families of the victims as he said the "thoughts of our city" were with them.
"This has already been such a challenging year, and this news of further loss of life is another terrible blow. As a city we will mourn for them," he added.
Prime Minister Boris Johnson said "our hearts go out" to the victims and their families, while Labour leader Sir Keir Starmer also offered his condolences.
GMB, the union for Wessex Water workers, said it is supporting all members and their families caught up in the tragedy.
John Phillips, GMB regional secretary, said "it is essential that a full and thorough investigation takes place at the appropriate time".
