Dozens dead, hundreds injured; naturally our thoughts turn to those immediately caught in the horrors that unfolded at 8am yesterday in Brussels.
Given the scale of the carnage it sounds trite to even mention this - but the more mundane and practical impact on ordinary lives will also be significant.
For those of us who spend much of our lives up in the air, things are going to be different. Not in the awful, agonising way of losing a loved one or living with a life-changing injury, but different.
As a result of yesterday's attack at Zaventem, persecuted passengers can expect heavier security every time we set foot near an airport terminal.
It will be annoying and it will be expensive. We already pay between €4 and €11 on every ticket for airport security,
They are going to make us more miserable and charge us more for it.
Security makes the process sound more sophisticated than it deserves.
The new world of air transport will simply mean screening, re-screening and re-screening again.
It will mean sniffer dogs and X-ray machines.
It may be time to take that belt off and leave it off altogether.
Like a general fighting the last war, the airport security industry has spent the last 15 years responding to 9/11.
The focus of the security industry has been to try to prevent another 9/11, ensuring sharp knives and, later, liquids, are not being carried on to an aircraft.
It has meant passenger records being taken and stored and passed to security personnel, who were not above leaking the information or using it for unscrupulous reasons themselves.
All that time and energy put into confiscating olive oil and toiletries may not have made us any safer.
But they were clearly looking in the wrong place.
Passenger details and airside screening have proved worthless in the face of the Zaventem attack.
Yesterday, the game was changed. Getting the bomb on board an aircraft is no longer the goal. Bringing one into the terminal will suffice for the new generation of terrorists. Airport management all over Europe will look at their own lack of preparedness for the equivalent of yesterday's attack.
Airport police were mobilised in Dublin and cars were stopped on the approach road. The purpose of this may have been a show of force.
It may simply have been there to reassure passengers. If security is not intrusive, people are indeed reassured. This is an opportunity for the security industry to win back the goodwill it forfeited so carelessly and aggressively in the aftermath of 9/11.
Passengers being screened more need not be as intrusive or time-consuming as it seems. This happens already at the world's more vulnerable airports.
At Tel Aviv, there is a security screen a distance from the terminal on the approach roads. Many major airports, including Bangkok, screen at the entrance to the terminal. Screening happens as passengers pass from landside to airside, which is universal, and the increasingly common fourth screening is at the departure gate.
Security is not as time-consuming as most of us think. In Dublin, the length of time passing through security is closely monitored to avoid delays.
If waiting times climb to 30 minutes, remedial action is taken. That system has been working very well over the years since T2 was opened.
It works well in the airports across Africa and Asia where screening on entrance to the terminal already takes place.
What lies ahead will also have to be tightly monitored. Dublin's 25 million passengers can be adequately screened. When it comes to Heathrow's 75 million, Charles de Gaulle's 66 million or Istanbul Ataturk's and Frankfurt's 61 million, the business of screening and re-screening will pose a whole new set of problems.
It is up to the security industry how they approach the new regime.
The steps that were taken after 9/11 were cavalier and intrusive.
In many cases, it did not stop short of harassing passengers.
In America, in particular, men with an incomplete high school education and a lot of power were given carte blanche to act as bullies and enforcers of a code that they made up as they went along.
The Transport Security Administration let it be known that they took complaints separately. But who would you complain to?
Journeys became more stressful. Those of us with frequent-flier cards and in the whole of our health could handle the stress.
Those with young children, and the elderly, were so intimidated that they reconsidered whether travel was worth the hassle. Air transport has been changed irrevocably by slaughter in Zaventem.
It is clear who the losers will be in the new changed game of airport security.
Brussels is the most international city in the EU. It's the heart of Europe. It welcomes people from every part of the world as international politics and business play out on a daily basis. Thousands of Irish people live here, working in the public and private sectors. It's a place where students hang out and genuinely feel a common European identity.