The site of the Malaysia Airlines plane crash in eastern Ukraine.
The shooting down of Malaysia Airlines flight MH17 over eastern Ukraine is a tragedy that strikes at the heart of every family.
Almost 300 people - babies on parental laps; world-leading researchers heading to Melbourne on their quest to fight AIDS; at least 154 Dutch, 43 Malaysians, 28 Australians and 12 Indonesians plus more; students, holiday-makers, businesspeople - have been innocent victims.
Lurking in the background of this appalling attack is Russian President Vladimir Putin. His support for rebels fighting the Ukrainian government has made the region among the most dangerous on Earth.
The geopolitical questions are clear: Is this state-backed terrorism? Why have European and US diplomatic efforts to stabilise the Ukrainian crisis failed? When will the global community unite to pressure Mr Putin and Ukrainian counterpart Petro Poroshenko to step back?
The answers are clouded by deep ethnic divisions between European-aligned nationalists who dominate western Ukraine and the government in Kiev, and the separatists in the east fighting for greater Russian language rights and closer relations to Moscow.
The best hope is that the scale of this tragedy will force all sides to recoil, allow an independent inquiry and return to the negotiating table.
But closer to the homes of every airline passenger, the deaths raise important questions.
Why were 283 passengers and 15 crew flown over such as demonstrably dangerous region? Were warnings significant? Why did some airlines avoid the area yet others, including Singapore Airlines, did not? Can Malaysia Airlines survive, following the disappearance of the MH370 four months ago?
Unless the global airline industry and regulators move quickly to reform processes and reassure air travellers, tourism and business will suffer.
Worse, myriad terror groups worldwide will rejoice.
The attack heralded a new front in the threat posed by terror groups. The usual shoulder-based missiles they use across the globe would not have reached MH17 as it flew at 33,000 feet across eastern Ukraine.
But the warning signs were there for MH17. On Monday, a Ukrainian military transport plane carrying eight people was hit by a missile fired from Russian territory, killing two of those on board. That missile struck at 22,000 feet - much higher than the altitude of usual military aircraft. The civil aviation regulator noted the importance of the strike yet increased the clear free flying space over the area from 26,000 feet to only 32,000 feet. The Russian-built SA-series missile suspected of downing MH17 and many other similar systems can reach twice that high - and the authorities must have known.
Every airline in the world will now recognise terror groups can gain access to longer range missiles. Even if they don’t, they can claim to. Airlines will no longer be able to take the risk that authorities and Malaysia Airlines did in letting MH17 fly across eastern Ukraine.
Unfortunately for those on board MH17, someone in eastern Ukraine had access to the potent ground-to-air missiles. The Russians say the Ukrainian government shot down MH17; some say Russia did; and most believe the Russian-backed separatists did by using the SA-series missile.
This is where the geopolitical problems become most difficult.
It remains possible this tragedy was committed by Russian-made missiles not supplied by Moscow but seized from the Ukrainian army.
Any solution is also complicated by the possibility that the rebels mistook MH17 for a military plane.
Civilian aircraft have been shot down by mistake before, notably when Korean Air flight 007 strayed over Soviet Union airspace in 1983 and Iran Air flight 55 flew in Iranian airspace in 1988 but US guided missile carrier USS Vincennes mistook it for a military aircraft.
Some social media posts following the MH17 explosion seem to suggest the separatists thought they were shooting at a Ukrainian jet. That could be propaganda, of course.
Mr Putin's response suggests he will argue that theory and blame Ukraine for resuming flights over the disputed area.
"I want to note that this tragedy would not have happened if there were peace on this land, if the military actions had not been renewed in southeast Ukraine," Mr Putin said. "Certainly, the state over whose territory this occurred bears responsibility for this awful tragedy."
Such rhetoric is backed up by the chilling warning - “We did warn you - do not fly in our sky" - that was posted on social media by rebel and former Russian intelligence offer Igor Girkin, who goes by the name Strelkov or "shooter".
Mr Putin must bear responsibility for allowing these groups to prosper and leaving open supply lines to them.
Prime Minister Tony Abbott was certain about who was to blame: “They (the militants) are Russian proxies essentially. This is only happening because Russia wants to stir up trouble."
That is true to some extent.
As the Herald said four months ago, Mr Putin must be condemned for sending his forces into Ukrainian territory earlier this year and fomenting unrest, especially in eastern regions and the Crimean peninsula to the south. Such bullying evoked the worst of Soviet era excess.
At the same time, the Herald said, an overreaction from the West could prompt the unpredictable Putin into even more extreme acts of aggression.
While Russia and Ukraine pulled back temporarily for a period, tensions have escalated in recent weeks with more flights by Ukrainian forces across the region and greater retaliation by rebels, including some based inside Russia.
The response from Europe and the US has been ineffective.
It was not until a day before the MH17 tragedy that US President Barack Obama announced tougher economic sanctions against Russia's state-owned power and defence giants.
Mr Putin was ropable. As such it will be difficult to find out the truth about Russia's involvement in the MH17 attack, especially if it has access to the black box flight recorder. Australia is well-placed to offer expertise as an impartial investigator, although Mr Abbott's strong and rapid criticism of the separatists may complicate any such offer.
Even without an inquiry, fundamental reforms are needed in the airline industry.
Authorities said it was acceptable for civilian aircraft to fly at over 32,000 feet over eastern Ukraine. We now know MH17 was an easy target at 33,000 feet and would have been at risk at virtually any altitude.
British and American aviation regulators had warned of the risks of flying over eastern Ukraine as early as in April, but failed to mention any threat from ground-to-air missiles. Indeed, British authorities were due to issue a new report on the risks in just two weeks' time.
Even without specific warnings, many other airlines, Qantas included, had stopped using flight paths across the region a few months ago.
Some aviation analysts suggest those airlines that did not shift routes took into account the cost and disruption to timetables. That's hardly reassuring.
Neither is the post-tragedy decision of Malaysia Airlines to stop using the route or the regulators' declaration of eastern Ukraine as the no-fly zone it should have become last November.
The only positive likely to emerge from this tragedy is a better global airline safety regime. It must recognise the increasing ability of non-state groups to engage in sophisticated warfare extending to ground to air missiles.
A less likely legacy of MH17 is a detente between Ukraine and the Russian-back separatists. It will all depend on how Mr Putin reacts in the days ahead. The international community must pressure him to co-operate fully with an independent inquiry and make clear that this is no longer an isolated territorial dispute between age-old foes; it is now a global crisis.
In response to news of stronger US sanctions against Russia on Wednesday, Mr Putin said: “It’s a great pity that our partners are following this path. But our doors are open for the negotiating process, for a way out of this situation.”
The world is hoping the human loss of MH17 will force those doors open wider, for the sake of the victims, the people of Ukraine and everyone who values safe airline travel.