Or it could be a terrorist attack like the Chechen one that killed like 200 people.
Indeed; but since I'm not a prurient spectator of mayhem, projecting ultra-high-definition morbid wish-fulfilment onto every piecemeal scrap of geopolitical narrative like some demented, salivating news-harpy saddled with a permanent rage-boner, I can actually withhold judgement during the twenty-four or so hours generally required for a glut of forensic and editorial opinion to surface from the usual multitude of sources, and thereby avoid needlessly corroding what little goodwill remains between secular society and the 99.9% of moderate, peaceable muslims whose sons and daughters are increasingly liable to form the vanguard of an ISIS incursion when your bannermen start pre-emptively rounding them up and herding them into ghettoes for being a certain shade of brown.
But hey: don't let reason and civility ruin your hard-on.