A fractured underground cast iron gas mains pipe has been blamed for the explosion which seriously injured a father and his three children and destroyed their house in Rathfarnham, Dublin, at the start of November.
Mrs Sandra Carrigan escaped with minor injuries in the blast which blew the roof and windows from her home in Glendoher Close in Rathfarnham on November 2nd.
Her husband, Mr Declan Carrigan, and three children, Laura (8), Sorcha (5) and Adam (3) were admitted to Dublin hospitals suffering injuries including severe burns and broken bones.
A report conducted by Mr Liam Ó hAlmhain for the Commission for Energy Regulation found that the cast-iron pipes had been laid over a filled-in ground over an old watercourse.
"The nature of the fill was such that the main was not adequately supported over its length," the report said.
The ground over the mains also contained "unsuitable materials" including ungraded builders rubble.
These factors caused stress on the pipe eventually leading to the leak which caused gas to accumulate under the Carrigan's house.
The report's recommendations to Bord Gáis included that it should review its cast-iron pipe replacement programme in areas of known ground settlement; set up a liaison with local authorities in relation to settlement problems; and review its safety procedures in relation to tracing and acting on leaks.
In a statement last night Bord Gáis said it would implement the recommendations, "promptly and effectively".
A programme to lay new polyethylene pipes throughout the Glendoher Estate was already underway, it said.
The Carrigan children are still in Our Lady's Hospital for Sick Children, Crumlin.
