WHEN her husband dialled 999 at 10.04am last Monday morning, Celine Cawley was barely alive. Minutes later, a squad car pulled up at the gates of Rowan Hill, a detached modern home on Windgate Road on Howth head.

The expensive electronic gates were shut. Gardai had to climb over them to get inside.

They walked around to the rear of the large house, where they found Ms Cawley, 46, lying on the cold patio paving, her flimsy night clothes providing little protection from the bitter morning chill.

Her face was badly bloodied and cut. Her arms and hands were bruised. She was conscious but comatose. A red brick spattered with blood lay nearby. Her husband, Eamonn Lillis, 51, was beside her.

Gardai tried to resuscitate her. The Dublin Fire Brigade's ambulance crew took over, when they arrived at 10.15am. Her life signs were failing fast: they strapped her into a stretcher and drove her to Beaumont Hospital where she died soon afterwards.

How had this successful boss of a production company, and mother and wife, met with such a violent end on the doorstep of her private, secure family home on a quietly exclusive road on Howth head?

Distraught though he was, Eamonn Lillis told gardai how he had found her.

He rose and dressed that morning, drove their 16-year-old daughter, Georgia, an only child, to school in Sutton Park for 8.30am. He returned to collect the three dogs to bring them for their customary morning walk around the hill of Howth.

He returned close to 10am to find a masked intruder and his wife injured on the patio. He lunged at the intruder and there was a brief altercation during which his skin was cut and scraped. The intruder ran off down the back garden, and onto a quiet pathway that leads to Carrickbrack Road.

Mr Lillis could not give a full description as the man wore a balaclava. He described the man as being in his 20s and of slight build.

Had Ms Cawley interrupted an attempted burglary?

Nothing was missing from the house. Some cupboard doors were still open, as though she was distracted in the middle of rummaging for something. Whatever the motive, this was murder.

At a press conference that evening, gardai appealed for witnesses. "We know, from what we've heard, the man ran down the back garden of the house, out on to a laneway and may have made his way in any direction after that but in particular the Windgate Road-Carrickbrack Road area," Superintendent John Gilligan told reporters.

Days passed, and despite dozens of reported sightings in the neighbourhood, a lead failed to materialise.

Mysterious walkers were not so mysterious after all: when traced by gardai, they turned out to be ramblers, walkers and locals who often stroll along this quiet, almost rural, road that traverses Howth Head. The roads and lanes behind Ms Cawley's house was closed off for days, as detectives hunted for some clue left by the intruder as he hurtled along his escape route. None were found.

There were other clues, though. A postmortem on Tuesday revealed not only how Ms Cawley died, but uncovered potential evidence.

She was hit repeatedly in the face and head with the garden brick. The attack was fast and frenzied, leaving Ms Cawley with little chance of survival. Although a former model, she gained weight in recent years and was no easy target for a man in his 20s of slight build. She fought back, as evidenced by the cuts and bruises to her hands and arms.

Strands of hair and shards of skin were found beneath her fingernails. Tests will show whether they belong to her killer, caught in her nails as she struggled to defend herself.

Tests will also show whether her killer's blood and sweat spattered the brick that was used to hit her repeatedly in the head.

Her night clothes were tested in the hope that fibres from his clothes, strands of his hair, even saliva and sweat, transferred on to her body during the sudden and frenzied attack.

There is also CCTV footage. Security cameras are common in the detached, gated homes along Windgate Road: other cameras at the nearby Summit Inn on Carrickbrack Road, may have picked up the killer as he made his escape.

The tests will take time but one thing is already clear: according to one officer, the trail of clues suggests that whoever killed Celine Cawley, did so in a moment of "spontaneous combustion".

Few people forgot Celine Cawley. She was good-looking, forceful and had a privileged family background to ease her path through life. Her father, James Cawley, was a well-known solicitor whose clients included some of Ireland's wealthiest businessmen. The family home was an impressive house in Portmarknock. Eamonn Andrews, the late television presenter, was a neighbour.

John and Kay McEnroe, the Irish parents of the American tennis star, were family friends. She was once said to have nabbed John McEnroe as her date to a dance in Dublin.

She went to the local convent primary school in Malahide -- then known as Scoil Iosa -- and from there to Cleremont convent, a private boarding boarding school for girls in Rathnew, Co Wicklow, which has since closed.

In her youth, she was a tall, striking beauty, her pretty face framed by a tumble of dark, wavy hair. Her accomplishments ranged from horse- riding and sailing to consummate style. One former student at University College, Dublin, recalled a perfectly groomed beauty who hung out with the wealthy set. "She was breathtaking: unbelievably glamorous," she said.

With looks like that, modelling was an obvious career path. She was 19 or 20 when she signed to Nan Morgan's model agency. One of her first jobs was a television commercial for ACC bank. "She really was a magnificent model," said Rebecca Morgan, who now runs the Morgan Agency founded by her mother.

"She really was beautiful. She really did do some beautiful work."

She was also forthright, focused and knew what she wanted, she added. "She would not have been a run-of -the mill model," said Ms Morgan.

Eddie Shanahan worked with Ms Cawley on shoots and fashion shows in the early 1980s before setting up his own agency. Even though he thinks her modelling stint lasted only three years, he put her up there with the Eighties model icons, Mari O'Leary and Barbara Cluskey.

She was, he said, "very independently spirited, very professional. I thoroughly enjoyed working with her. She was a girl who, while very good in the fashion business, wasn't seduced by it. She wasn't a silly airhead. She was one of those girls who came to the business when modelling was in transition from the years when models turned up at any hour of the day in full make-up, hat, gloves and two-piece suits. She was one of the first breed that began to dress with more freedom and brought a personality to the job," he said.

"Celine would turn up in jeans and a t-shirt, just like Mari or Barbara, and they would paint on the face for the performance and deliver it with great aplomb. They were their own women, all of those girls."

Mari O'Leary, who now runs her own public relations company, still has a vivid mental picture of Ms Cawley 25 years on. "My memory of her is as a real, natural beauty. She knew her own mind. She was refreshing. She was quite focused on what she wanted to do," she said.

Her ambitions stretched beyond Irish shores. Ms Cawley moved to New York in 1982, where her parents' friends, John and Kay McEnroe, took her under their wing. The Sunday Independent's social diarist caught up with her breathless lifestyle. She told how she had modelled for Vogue, Elle, Christian Dior, Chanel and Pierre Cardin.

The names of celebrities she met tripped off her tongue: Bruce Springsteen and Ryan O'Neal, Jacqueline Bisset and Bjorn Borg. She wasn't shy in sharing her opinions of them either. Actress Brooke Shields was an "air head" who was "getting heavy on the hips".

She was later to experience her own weight problems, but back then, such brassy confidence was typical of the young woman for whom doors kept opening.

Back in Dublin, she planned her exit from modelling. In 1985, she landed a fleeting role in a Bond movie. It was a walk-on, non-speaking part in the 007 movie A View to a Kill, in which she had to give Roger Moore the eye.

Acting fascinated her, according to Rebecca Morgan, but being on the other side of the camera stimulated her even more. In a tribute to her last week, Peter Brady of Windmill Lane studios recalled how she got her "first break in to this industry" when she "worked on reception here but was very quickly poached by a production company client who spotted her true potential".

She moved to London, worked on TV dramas such as London's Burning and the detective show, Pulaski in 1987. That led to a gig as a commercials producer for Gerry Poulson's company, GPA Films.

Aged 28, with single-minded focus she set up her own production company, Toytown Films, in 1990. She had already met her husband, Eamonn, by then. A mild-mannered art college graduate, he worked as an advertising copy writer and later produced commercials. They married in 1991 in the Church of the Assumption in Howth.

Within a year, the company was formally incorporated with Celine as managing director and Eamonn a director and a producer for the firm. The same year, their daughter, Georgia was born.

They were opposites in some ways: friends last week described how his quiet manner countered her forthright personality. His temperament was quiet and artistic, she was formidable and feisty. "She was certainly the driving force in the business," said one source close to the case.

In the fraught and competitive world of advertising production, her success was no mean achievement. She brought Toytown to the top of the ladder. Her clients had some of the fattest advertising budgets in town: Diageo, Coca Cola, Heineken, Volkswagen, Carlsberg, 02 and the National Lottery. She expanded the business, providing production facilities for international commercial production crews on location here. It was a lucrative move. The company's profits soared in 2007 to €270,000, up from €67,000 the previous year.

For all of her feistiness, she inspired enormous affection. It was there in spades in the tributes posted by colleagues on the Irish Film and Television Network website. John McDonnell, a producer and friend, wrote: "She was always available with words of wisdom and comfort as you deal with the many obstacles that life throws at you. We worked together for many years and we referred to her affectionately as 'Mum'. She was a unique person with a heart of gold."

Keith Hutchinson from H2 Films, said he was "always amazed by Celine's kindness of spirit. Always the first with words of congratulations, or to send a gift for a newborn child or a wedding. It's this kind of thoughtfulness for others that is a true reflection of the person that was Celine".

Ms Cawley no doubt knew the importance of a kind gesture, having lived through tragedies of her own. Her sister, Barbara, died several years ago, after a long illness. Her mother, Brenda, died over a year ago.

Ms Cawley and her remaining siblings, Chris and Susanna, and their father, James, were close. She often worked with her brother, Chris, who was also a big player in the advertising game as executive chairman of Cawley Nea/TBWA Advertising. Her father joined a legal practice with Susanna and her husband in Kildare.

Those tragedies were in the past. Eamonn Lillis and Celine Cawley had much to look forward to. The business was doing well. Their daughter, Georgia, was growing into a beautiful young woman, who like her mother loved sailing and horse riding. Georgia had been trying to sell her old dinghy -- a white Pico with blue sails -- at Howth Yacht club for €2,400.

The day before she died Ms Cawley took Georgia horse-riding at Broadmoor Equestrian Centre. She spoke about buying her daughter a new pony.

Less than 24 hours later, the charmed life of pony clubs and sailing clubs, the success she had built up, the views she enjoyed of her beloved Howth, were shattered in an instant.

Eamonn Lillis is bereft of his wife of 17 years, while Georgia, their only child, is grieving for her dead mother at a time when she should be concerned with innocent fripperies that go with a teenage Christmas.

Ms Cawley's body is expected to be released to her family for burial early this week.

- Maeve Sheehan