Ariana Grande has told her fans she is "thinking of you" on the four-year anniversary of the Manchester bombing.On 22 May 2017, a bomb exploded at Ariana's concert in at the Manchester Arena, UK, killing 22 people including many children."Although grief is ever-present and our relationship to it is constantly evolving and expressing itself in different ways every day, year round…. I know that this anniversary will never be an easy one.