megamanfan43 helped me with this.
 
Lightning Dust and the other Washouts were practicing their routine in a gorge but when a loose stone had fallen it landed on Lightning Dust’s wing but instead of Helping her the other washouts just said to her “You’ll just drag us down” and left her alone, Lightning just felt betrayed and tears flowed and being there really made her look at where her life had taken her and she finally realized what the hell was she doing?!
 
Rainbow Dash saw her and Lightning tried to put on her usual stance acting like she could take it but Rainbow could see right through it and Lightning just broke down, Rainbow Dash never saw her like this before Lightning practically poured her heart out and told Rainbow what happened and though she had every right to leave her for what she did, she knew she wouldn’t be any better than they were and took Lightning to the Hospital to get her injuries taken care of, now Lightning Dust is slowly getting her life back together but is a lot happier