A woman whose father and two brothers died in a slurry pit accident has said love for her family drove her to twice enter the fume-filled tank in an attempt to rescue them.

Ulster rugby player Nevin Spence, 22, his brother Graham, 30, and their father Noel, 58, died at the family farm near Hillsborough, Co Down, last September.

An inquest in Belfast heard the incident was first triggered when Graham Spence entered the tank to find a collie dog that had fallen in.

Emma Rice was also overcome by the poisonous gases when she climbed down a ladder to try to find her father and brothers.

She told Northern Ireland's Senior Coroner John Leckey that she knew how dangerous it was to go into the pit.

"When it comes to the love of your family, it doesn't matter," she said.

After helping to pull her father out, Mrs Rice passed out and fell back into the slurry as she tried to help Graham.

She was rescued by neighbours who had rushed to the scene to help.

Mr Leckey said Mrs Rice's actions were "extremely brave".

The court heard that the young artist initially fought off the attempts of neighbours to stop her entering the tank, which was dark.

"I remember thinking they're not going to live in there, so it was just get them out," she said.

Mrs Rice's sister Laura and mother Essie were also in court for the first day of the inquest.

The incident happened just after 6pm on 15 September 2012.

The inquest was told that Nevin and his brother had been working in the farmyard loading wood into the Ulster star's car, helped by friend Andrew Oliver.

Mr Oliver and Nevin then went into the farmhouse after the rugby player's mother called him for his dinner.

Shortly afterwards, Noel Spence came into the house and said the dog had fallen into the tank.

The tank was located under a shed that housed calves.

Accessible through eight manholes, it was around 3m deep and, at the time of the accident, there was around 1m feet of slurry at the bottom.

The men went to the shed and lowered a ladder into one of the manholes. Graham climbed down with a torch and conducted a quick search for the animal.

In his statement, which was read to the court in his absence, Mr Oliver said: "After about 15 to 20 seconds it looked like Graham was giving up the search."

He said he then started climbing up the ladder again.

"At the point when his head was just about at ground level - he had looked fine until then - he passed out and sank back into the tank."

Seeing his brother fall into the slurry, Nevin then climbed down. Mr Oliver rushed off to call for help.

Shortly afterwards, the Ireland under-20 international also succumbed to the poisonous fumes and collapsed into the slurry.

Noel then went down into the tank. He managed to retrieve Graham and began carrying him back up the ladder. Mr Oliver grabbed hold of Graham's clothing from above as his father climbed upwards.

"Noel was overcome and fell down the ladder," he said.

"I wasn't able to hold Graham without Noel's help."

Mrs Rice and her husband Peter had been visiting Graham's wife Andrea at their house nearby when the accident happened.

As they were leaving, they noticed a car speeding up the drive and went after it to see if something was wrong.

In her statement, Mrs Rice said she ran round to the shed to investigate while her husband parked the car.

"I think I remember someone saying "They're all in the tank"," she told investigators.

"Someone tried to move me away, I stopped them and got on to the ladder."

Mr Oliver and neighbour David Wilson both tried to prevent the young woman entering the tank.

When she first climbed down, Mrs Rice located her father and, by grabbing the belt on his trousers, managed to lift him up. She was helped by neighbours to haul him up and out of the pit.

Having recently taken a first aid course, she attempted mouth-to-mouth resuscitation.

"I then went back to the ladder and again went down a couple of steps," she said.

On that second attempt, she found her brother Graham and tried to lift him out.

But as she emerged out of the pit, she was overcome by the gases.

"I suddenly felt faint and sleepy," she said.

"The next thing I remember, I was in the recovery position."

Rescuers finally managed to get both Mrs Rice and Graham out of the tank, but the search for Nevin went on.

A firefighter wearing specialist breathing equipment later found both Nevin and the dog at the bottom of the tank.

Despite frantic efforts to revive the men, Nevin and Noel Spence died at the scene, with Graham declared dead in hospital a short time later.

Mrs Rice was taken to the Royal Victoria Hospital in Belfast where she recovered sufficiently to be discharged to deliver a moving tribute to the men at their funerals.

During the first day of evidence, a number of neighbours described how they had responded to calls for help and tried to rescue the men at the Drumlough Road farm.

Mr Leckey said it was "incredulous" that they had managed to do what they did and pull three adults, their clothes soaked in slurry, from a gas-filled underground pit.

"You are all extremely brave, you all made frantic efforts to effect a rescue," he told one witness.

After hearing how the tragedy had unfolded, the coroner asked Mr Wilson was he aware of the dangers of slurry gases.

"I think we're all aware of the dangers but on the spur of the moment these things are done without thinking," he replied.

Mr Leckey said the Spences had shown an "understandable desire" to save the dog.

"I think everyone's instinct would be to try and rescue a family pet," he said.

But he later asked Fire Service Group Commander Dermot Rooney for his opinion of health and safety legislation, which stated that an individual should only enter such a confined space in exceptional circumstances, and then only with the aid of breathing equipment.

"I would absolutely be in concurrence with that," replied Mr Rooney.

The officer said a gas sensor was placed in the shed while the rescue was ongoing. It briefly sounded, indicating a level one warning.

"If it had gone to the second level I would have had no choice but to evacuate the area," he added.

Mr Rooney said slurry emitted a number of harmful gases, including hydrogen sulphide, carbon monoxide, methane and ammonia.

Mr Leckey said he was concerned at the number of recent cases he had dealt with involving deaths at slurry pits, describing the situation as a "very serious problem".

Northern Ireland's state pathologist Professor Jack Crane and investigators from the Health and Safety Executive are scheduled to give evidence when the inquest concludes tomorrow.