As a vigil is held in London to commemorate the victims, how easy is it to unite after a terror attack?
18 January 2017, 15:56
This is how to let the emergency services know you need help when you can't speak.
The 999 Info That Could Save Your Life
Whether it's a violent person nearby or an accident that leaves you out of breath, there are still ways to let the 999 responder know that you're in trouble.
Watch the video above.