An architect's practice and a construction company have been fined £195,000 after a man died during the building of a Somerset business park.

David Cairns, 64, was working on the air conditioning plant at the newly-built Exchange building at Express Park in Bridgwater, when he fell 30ft to his death in January 2005.

In his youth Mr Cairns, from Gwent, Wales, had pulled schoolchildren to safety during the Welsh Aberfan disaster.

Mr Cairns, who leaves a wife Judith, daughter Lisa, and son Jonathan, was one of the first on the scene at Aberfan.

He helped save the lives of several children at the 1966 disaster, which killed 144 people, 116 of them children.

He was due to watch both his children get married the summer. His wife Judith said: "In times of stress he had the gift of saying the right thing.

"He was my best friend, I will miss him so much. Life for me will never be the same again."

When the tragedy occurred, Mr Cairns was working on the plant, which was built on a platform that could only be accessed via a ladder at the edge of a flat roof.

The roof only had a low parapet, which was not high enough to prevent Mr Cairns falling.

He was later pronounced dead at Musgrove Park Hospital.

Express Park Construction Company Limited (EPCC), pleaded guilty to breaching Section 3(1) of the Health and Safety at Work Act 1974 for failing to safely manage subcontractors working for it.

The architects involved, Oxford Architects, pleaded guilty to breaching Regulations 13, and 14, of the Construction (Design and Management) Regulations 1994, which require designers to take safety considerations into account.

EPCC was fined £75,000 and ordered to pay costs of £68,000 and Oxford Architects Partnership was fined £120,000 and ordered to pay costs of £60,000 at Bristol Crown Court.

Mr. Cairn's family, who were at court, said: "The loss of David has deeply affected us all and he will be greatly missed. Our hope is that lessons are learned within the construction industry so that other similar incidents are prevented.

"Safety should be paramount during all stages of the building process so that another family doesn't have to suffer the loss that we have."

HSE Inspector Sue Adsett said: "This is a tragic case where the failings of the construction firm and architects led to Mr Cairns' death."