Peter Kassig's death is an individual tragedy - an act of almost baffling brutality.
However, it does not surprise security officials here in the US.
The President, who will be back in the White House from the G20 summit in a few hours, will meet with his advisers, trying to assess how the war with Islamic State is going: are these airstrikes proving effective?
Perhaps the greatest single concern to security officials are reports from the Middle East that the fractured jihadi groups in the region are now beginning to show a united front.
That would clearly pose a very potent threat both to Europe and to the United States.
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Police now say they believe Michael Zehaf-Bibeau did act alone, in other words this was the classic lone wolf attack that is so difficult to prevent and to anticipate.
Zehaf-Bibeau was not one of the 93 so-called aspirational jihadist who was actually under active surveillance but he had applied for a passport and that application had been denied.
Police are now saying that it may have been that setback that actually triggered the attack on parliament. In other words it was an act of fury for not being able to join the jihadist struggle in the heartland of Iraq and Syria.
But for counter terrorism officials and for police far beyond Canada, the question is how many others may still try and emulate what Zehaf-Bibeau did here yesterday.
According to police it does seem increasingly likely this was some sort of lone wolf style operation by the gunman. But we still don't know if he had a network of supporters and even whether he had an allegiance to the Islamic State.
Frustratingly he was on the radar screen of counter-terrorism officials. Not under active surveillance but we believe that he'd applied for a passport and been denied it.
Talking to MPs here today I got the sense, paradoxically, of relief, many thought that without the intervention of the Sergeant-at-Arms this tragedy would have been a great deal more serious.
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It has now been confirmed that the remaining patient here, Nina Pharm, also known as 'Nurse 1' will be transferred from this hospital to a specialist unit in Maryland, just outside of Washington DC.
I think here everybody recognises this is has been a public health and a public relations disaster, but less talked about and probably more significant is how valuable a lesson this has been.
Really teaching everybody around the world that however sophisticated your medical infrastructure is, when it comes to the Ebola virus nothing really beats good preparation and excellent education.