On Wednesday afternoon, the BBC reported that a car had driven through the crowd on Westminster Bridge, and photos of the chaos outside London's Parliament show a disturbing scene. This attack was reportedly followed by the stabbing of a police officer in the Houses of Parliament in central London. In a statement to members of Parliament, House of Commons leader David Lidington confirmed that the alleged attacker was shot by armed police.
Police were called to the scene just before 3 p.m. local time on Wednesday, responding to reports of the car on Westminster Bridge and a man armed with a knife. The situation is still developing, but the Metropolitan Police declared the attack a "terrorist incident." Immediately following the attack, Parliament was put on lockdown, and police asked the public to avoid the area to allow medical personnel to deal with the aftermath.
In a statement given later, Commander BJ Harrington at New Scotland Yard announced that there had been a "number of casualties, including police officers," but he could not confirm their number. However, the BBC reported that a woman has died, and there appear to be several other injuries.
The investigation is ongoing — in fact, it's just begun — but photos from the scene, including those posted to social media, paint a chaotic picture.