Ferry gases 'freed by stormy seas': 'A million-to-one chance' led to the deaths of two children on the Celtic Pride, an investigation by Irish officials found. Alan Murdoch reports

Malfunctions in the sewage storage system lie at the heart of the tragedy in which Katherine Tomlins, 15, and her brother James, 12, died during a ferry crossing from Swansea to Cork.

Seamus McLoughlin, deputy chief surveyor in the Irish Department of the Marine, who led an examination of the boat in Cork harbour, concluded yesterday that the two children inhaled toxic sewage gases released in the Celtic Pride during a stormy 10-hour voyage. He believed that the fumes were released by 'an unfortunate combination of different circumstances'.

He said water in the bowl of the lavatory prevented toxic gases from entering cabins. But water in the children's lavatory had disappeared, possibly because of the rough crossing on Tuesday night.

'We are speculating that a number of things happened at the same time. Perhaps a number of people flushed their toilets at the same time which may have created a partial vacuum in the main sewage system. That itself would not have been enough, but perhaps if the ship struck a large wave or took a roll, these things all might have done.'

Mr McLoughlin suggested the ventilation system in the cabin may have been turned off, perhaps because of the cool temperature or its noise, allowing a fatal accumulation of gas in the children's cabin. He said he had not been able to establish definitely if the ventilation had been switched on or off at the time the bodies were discovered.

A vacuum effect within sewage pipes could have helped cause a surge of gas into the cabin. The Celtic Pride has an older 'gravity' sewage system similar to that of domestic houses, as opposed to the vacuum suction system installed in more modern ships where gas cannot get back into cabins.

Mr McLoughlin said he did not think the accident could have been anticipated. 'But even that one-in-a-million chance has to be eliminated,' he said. He declared 'absolute satisfaction' that the problem with the ferry had now been overcome.

But yesterday there were reports from passengers suggesting that there had been earlier problems on the boat.

John Marks, who travelled on the Celtic Pride at Easter last year, told the Independent of similar sewage problems occurring, also on the ship's C-deck.

'We were coming back from Cork on the Celtic Pride, and the weather was particularly rough with Force 8 gales. During the night we heard these gurgling noises and had the same bad smells. In the morning we found all the sewage bilge was coming up through the toilets and showers,' Mr Marks said.

He said that among the crew he encountered only the purser spoke English, which discouraged passengers from raising the matter with other crew members. But cabin staff who woke passengers early prior to docking in Swansea must have encountered the smell.

Dr Garret Fitzgerald, the former Irish prime minister, yesterday recalled a similar gas build-up on a different ferry in 1980 and asked whether the occurrence was indeed a 'one-in-a-million' chance.

He said he and his wife had been travelling from France to Ireland in August 1980 when the water in their cabin lavatory had disappeared and 'an appalling smell' drove them to ask for a different cabin. None had been available. 'It wasn't a matter of great surprise to the crew. We were told it happened from time to time,' Dr Fitzgerald said.

Passengers on Tuesday night's crossing to Cork said occupants of up to 25 cabins on the middle C- deck had been sick in the early hours of Wednesday when affected by a 'strong stench'.

John Parcell, an executive with the Reuters news agency, was in a cabin close to that in which the Tomlins children died.

He reported noticing 'a sweetish sewerage smell' in the early hours and later seeing a deluge of sewage pouring down the stairwell near where the deaths occurred. He said the smell became very bad around 4.30am to 4.45am and his wife had alerted crew. They brought a wet and dry vacuum cleaner and air freshener, but the smell had persisted, he said.

John Dale from Epping, also reported seeing sewage on the stairs near the casino and bar area, covered with a white powder.

His family noticed a strong sewage smell in their C-deck cabins. They had difficulty getting their lavatories to flush in either cabin and had heard a gurgling, bubbling sound coming from the lavatories.

The 7,800-ton ferry has a crew of 110, four of whom are Irish and the rest Polish, and a maximum capacity of 1,000 passengers. Built in Nantes, western France, in 1972, it has 440 berths and space for 155 cars. It returned to Swansea yesterday with 446 passengers and 110 cars.

Overnight work had been carried out on the sewage system, and the cabins affected sealed off for the return trip to Swansea. This included modifying the ventilation system so that it cannot be shut off in certain areas.

(Photograph omitted)