Marius Badiou died on 21 July 2022 during a lifting operation at the Gatwick Railway Redevelopment Project at Gatwick Airport.
A joint investigation was launched with and led by the British Transport Police. The police have concluded their investigations and HSE will now lead the case.
The investigation will determine if any breaches under the Health and Safety at Work Act have occurred.
HSE principal inspector Ross Carter said: “It is important HSE completes the investigation into Marius’s death to determine the cause of this incident.
“HSE will draw upon the evidence gathered so far and call upon its own specialist investigators and independent support in what is likely to be a complex investigation.
“During the investigation we will continue to keep in touch with Marius’s family as we send them our deepest sympathies at this difficult time.”