A special concert is being held in Manchester this Sunday to remember the victims of last week's attack.
Twenty-two people died after Ariana Grande's concert in Manchester Arena.
The One Love Manchester gig brings together some of pop's biggest stars to raise money for those affected.
Here's everything you need to know - and if anything in the news upsets you, check this out.
Justin Bieber, Katy Perry, Little Mix, Coldplay, Miley Cyrus, Take That, Usher, Robbie Williams, The Black Eyed Peas, Pharrell Williams and Niall Horan will all be performing at the concert.
They will be joining Ariana Grande, who wanted to organise the concert to raise money for the victims of the attack.
It's taking place at Lancashire Cricket Club's Old Trafford ground in Manchester.
Fans who were at Ariana's concert when the attack happened have been given free tickets.
However, Ticketmaster, who are in charge of the tickets, said that 10,000 people falsely claimed they were at the Manchester attack in order to get free tickets.
They said they are "doing everything we can... to ensure that tickets go to the actual fans and not the opportunists or touts who have also been applying for free tickets".
The rest of the tickets were sold to raise money for the We Love Manchester Emergency Fund, set up by Manchester City Council with the British Red Cross.
Those tickets sold out in 20 minutes online when they went on sale on Thursday.
For people who didn't get tickets, the concert will be broadcast live on BBC One on Sunday from 6.55pm and on several BBC radio stations.
It will also be available to watch on the BBC iPlayer.
It will be hosted by Strictly's Ore Oduba and DJ Sara Cox, with Nick Grimshaw and Anita Rani hosting from backstage and in the crowd.