Board Thread:The Flash discussions/@comment-9346948-20160525000159/@comment-26537965-20160528125702

Diagonally33 wrote: The future will happen not matter what you do. In Legends of Tomorrow, Rip's family dies even after the team saves them and Captain Cold's dad went to prison even after he made sure that he won't go because of steeling.

So Barry's mum will still die in a different way and as we know Barry because Flash but later in 2020. Being affected by the particle accelerator explosiin is what caused him to become the flash, not his mother s death. Just because we knoe that in the original timeline he still became the flash, but in 2020 that does not mean that she died at some point piror to 2020.