Three years on from the collapse of the Didcot Power Station, hundreds of tonnes of evidence is still being investigated. Tonight, Thames Valley Police says it's committed to getting answers for the families of the four men killed.
Demolition workers - Michael Collings, Chris Huxtable, Ken Cresswell and John Shaw- all died when part of the boiler house collapsed on top of them on February the 23rd 2016.
It took several months to recover their bodies and a multi million pound investigation into what happened is still ongoing.
Almost 2000 witness statements have been gathered and nearly 900 tonnes of material has been removed from the site.
Watch this special report by Emma Wilkinson:
It was one one of the country's most prestigious demolition projects.
Dozens of workers bringing down the historic Didcot A Power Station.
However in February 2016, 4 never walked away.
1094 days have since passed, but still there are no answers.
The investigation has now moved off the site of the collapse with 870 tonnes of evidence moved to the Health and Safety Executive's Science division facility at Buxton Derbyshire for further forensic examination. A team of experts continue to analyse thousand of exhibits and work through complex technical data which take significant time to analyse and interpret.
In 2016, relatives of the men were angry about the speed of the recovery operation.
The collapsed structure was initially too dangerous to approach, so it took six months to get all the bodies out.
Now all the families can do is wait - MPs have been keeping up pressure on their behalf.
Sarah Champion, MP Rotherham, Lab:
More and more old power stations are being shut down, so answers about what went wrong at Didcot are eagerly awaited by the industry too.
The company behind the demolition said it would be remembering its colleagues privately for this anniversary.
For the local community, it's also had a lasting impact.
Ed Vaizey, MP Didcot & Wantage, Con:
A memorial likely won't happen until the investigation has finished and the wheels of justice are turning slowly.
The concern for some is there doesn't seem to be an end in sight.