Police and health and safety experts were today probing the death of a young father from Bradford on a building site.

Labourer Mark Anthony Wroe, 22, of Holme Wood, was struck on the head by a two foot square block of masonry that fell 15ft.

Mr Wroe, of Knowles Lane, had been part of a team renovating an old mill at Water Lane, Stoney Royd, Halifax.

It is understood that part of the building collapsed yesterday, sending blocks of stone crashing on top of the workers.

Two of Mr Wroe's colleagues were treated in hospital for shock and a third man received leg injuries.

Firefighters rescued the workmen from beneath the rubble when they arrived at the scene, but could not save Mr Wroe.

"It is thought that the gable end of the mill collapsed on top of the men," said a spokesman for West Yorkshire Fire Service.

The construction workers were renovating an old mill and widening a stone archway when chunks of masonry, about 2ft square, fell 15ft on top of them.

Debris spilled out on to Water Lane which was cordoned off by police.

Officers confirmed that a full investigation had been launched alongside the Health and Safety Executive.

Today Detective Inspector John Hoyle of Halifax Police said: "Our sympathies go out to the family. They are distraught. Mr Wroe went out to work yesterday morning, and they expected him back at teatime. Instead, they were contacted by the police to be told this terrible news, which was a shock for them.

"They will be trying to come to terms with this over the next few weeks and no doubt they will have a number of questions to ask about how this happened."

He said he understood Mr Wroe, who was employed by the mill's owners, Wharfedale Finance, had been working on the site for about two weeks.

He could not say how experienced he was in construction.

"Mr Wroe was a working man who went out every day to earn a living for his girlfriend and three-year-old child," said Det Insp Hoyle.

"Unfortunately, on this occasion he did not return home."

A post mortem has been carried out and an inquest into Mr Wroe's death was expected to open and be adjourned today.