It's every parent's unuttered nightmare — the thought that your child might die before you. They're young, they're healthy, with their whole life seemingly before them and then, in an instant, like the five young British girls in Ecuador, death snatches them from you.
My father once told me that worry is not an emotion that a parent can control, that whether your kids are five or 50 you worry about them from the day they are born until, well ... hopefully and statistically, until the day you die and they move centre-stage.
Will they get over the chicken-pox? Where are they at 3am?
Or, later still, you hope that job/mortgage/spouse-to-be works out for them. That and a million other silly things. It's called being a parent.
When I was not much older that 20, I took myself off to a far-flung corner of Africa to cut my teeth in journalism in a war zone. These were days without email, mobiles or texting, and landline phones — when you could get one that worked — were expensive.
And so for months on end I had no contact with home and it was only by watching the daily papers for my byline from abroad that my parents had any inkling that I was safe and sound. I never gave it a thought. I was young. And, like all young people, I was invincible.
Today, the world is a much, much smaller place. Communications are instant — and cheap, as is airline travel, so it is little wonder that more than 250,000 young people from these islands annually take what is euphemistically called the Gap Year.
And what parent would begrudge them their year of freedom, of hanging out, of traipsing through jungles and tubing down murky, disease-infested waters?
The world is, literally, their oyster, and a year out travelling is in itself a wonderful addendum to their education. And, because the world is a smaller place, you are lulled into a false sense of security about their safety. They are, after all, just a mobile call away.
And so they go, but we as parents still worry. And the wretched sadness and sense of hopelessness with which the parents of Ecuador victim Indira Swann faced the media this week only reinforces in every parent that worry.
But, as a parent, you have to let go, as I did earlier this year with my eldest son who, at 23, had spent five long years at college and wanted his year out.
His mother was bordering on hysterical almost. My fears, though no less founded, I kept in the recesses of my mind.
He kept us up to date with generous email accounts of his travels around Asia — and then, suddenly, there was silence for almost a week. You imagine the worst.
And though, now thankfully, he is sound in mind and body, he was struck down with Typhoid Fever in some far-flung island off Vietnam and ended up in a makeshift clinic without the proper facilities to look after him. He was drifting in and out of delirium with a temperature of 104.
Thankfully his friend stayed with him. But mobile communications were not great, the clinic's staff presented a language problem and, then, the insurance said they had no record of his cover. So we had to bring in the Irish Department of Foreign Affairs, and the Embassy, and consulates and all the time we worried ourselves sick ... and the more we learnt about Typhoid Fever, the more we worried.
But now, he is back home recuperating and his mother is like a new woman.
His plans to continue his journey in a month or two seem lately to be low on his priority list.
He now seems more intent on getting a 'proper job' at home with his degree being put to good use. And, if I am honest, I'm a happier parent for that.
If they are intent on going, then go they must. But it only takes a step onto an unfamiliar roadway or a coach to your next stop-off to make it all go horribly wrong.
Something all the parents of those five talented young girls learnt this week. And something they are going to have to learn to live with for the rest of their days.
... but Gráinne McCarry says it's the trip of a lifetime
When I look back on my round-the-world trip, my most memorable moments were of all the new experiences I gained along the way. I will most likely never have the opportunity to repeat the adventure but, when the going gets tough, I love to think back to the highs and lows of my travels.
Growing up, I always had a trip earmarked and spent endless hours dreaming about jetting off around the world. Once I had booked my flight, the departure date couldn't come quickly enough.
I set off with four friends, heading first to Kuala Lumpur. We had two months scheduled in south east Asia, making our way through Malaysia, Singapore, Borneo, Thailand, Vietnam and Cambodia and then on to Perth in Australia for a year of sunbathing and occasional work.
I have lots of great memories, and nostalgia has a habit of making the not-so-good moments appear rosier too. Bad experiences included get robbed, robbed and robbed again, and the never-ending search for work in Australia.
However, when I think of camping under the stars at the red centre of Oz and hiking around Uluru, Kata Tjuta and the Olgas, or abseiling down a waterfall in the outback, those thoughts are far from my mind.
For me, the trip was intended to broaden my horizons and to meet new people, and I certainly did that. When things were going slightly pearshaped, I reminded myself that someday I would be able to laugh about it — I just didn't expect trouble only minutes after touching down at Kuala Lumpur airport.
Our driver was trying to read our hostel directions and break the speed limit at the same time. He turned around to chat and the pages, including our booking confirmation, blew out of the window and up the motorway.
He didn't seem fazed by this at all, he simply pulled up on the hard shoulder and walked up the motorway — at his leisure. Never mind that it was the middle of the night and we had to be at the hostel at a certain time. He was gone for at least 20 minutes, eventually returning without it.
In the end, he phoned a few hostels and our booking was confirmed. All that and we had just started our trip.
That our first potential disaster had been averted, after a few prayers, was the yardstick by which we measured all other hairy moments, of which there were many, along the way. Another time we decided to educate ourselves in Hindu culture. We set off on the local bus to the Batu caves in the northern suburbs of Kuala Lumpur, where the Thaipusam festival is held.
A DIY trip was a much better idea than those expensive guided tours for the rich tourists, we thought. We were proper backpackers on a budget, so we hopped on the bus with the school kids.
Little did we know, but the date changes every year, according to the Tamil calendar, so we arrived a day late and missed all the fun. We were greeted by what looked like a deserted field of litter.
However, we persevered and climbed the 272 steps to enter the spectacular limestone caves and were promptly set upon by wild monkeys foaming at the mouth. We came down the steps faster than we climbed up them — a pretty hard thing to do when you're wearing flip-flops. After that, we stuck to guided tours.
Travelling taught me to appreciate the small things in life — like electricity and hot water.
We were staying up a mountain in Cambodia and the highlight was watching the sun set over the paddy fields with Vietnam on the horizon.
Then the power went out and we had to put up with ice-cold showers and had to go to bed early by torchlight on a Saturday night.
Counting pennies got pretty monotonous, and I was fed-up being asked about the Troubles.
That stopped in Australia, though, everyone we met was from Ireland!