The attack in London on Westminster bridge was all but ignored in the news in the U.S. until a couple of days after the occurrence. Only a year ago, something like this would be picked up immediately on all television stations in the U.S., and reported on throughout the day. Such is our world that we now expect these events to occur regularly and be commonplace.
It seems that Londoners might expect some change within their government for prevention in the future, if this is going to become routine, particularly since one of their MPs who was carrying no weapon was knifed to death on the scene. The astrological support for this idea of expectation is, I believe, held within the Spring Ingress chart for London, just 2 days prior to the attack.
In the Ingress chart, we see the Moon Nodes exactly on the MC, suggesting that it is the "people" who will bring a force upon the government to take action. What strikes me most about this Ingress (everywhere) is that the Moon is so closely conjunct to Saturn, which, btw, is at galactic center( a rather separate and esoteric story which I won't elaborate on here and now). The sabian degree for 27 Sagittarius is "an old bridge over a beautiful stream, which is still in constant use". The Westminster bridge is an old bridge which is painted green for a reason - because it matches the color of the House of Commons in parliament. It is the "people's bridge", the commoners bridge, constantly in use. I don't think that Londoners will take the same attitude which the Parisians took. I don't think they will accept so easily that this may happen again and again while they go about their daily business. The Saturn and Moon are in the 6th house, which in mundane astrology is the house of enforced discipline, all civil service people who attend to orderly control within the scope of the government.