Detective Chief Inspector Dick Pearson said: "These deaths are being treated as unexplained. The full circumstances of this tragic work-related incident are being investigated by the police with the assistance of the Health and Safety Executive."
More top news
Dry and sunny tomorrow and feeling warm.
Mild tonight with warm sunny spells and light winds tomorrow.
A section of the M3 has been closed and bomb disposal units are at the scene after reports of "potential hazardous material in the road".