Coworker Jenna "accidentally" deletes employee's entire client campaign folder the day before a major pitch, then lands the promotion they were both competing for: ‘It was a mess’

It's hard to move in when someone else's mistakes cost you everything.

After spending more than a month preparing a major client campaign, an employee discovers the entire project has been deleted just one day before the final pitch. A coworker claims it was an accident, management brushes it off, and despite scrambling to rebuild everything overnight, the team loses the account. To make matters worse, that same coworker later gets the promotion they had both wanted.

I'll never understand those employees who mess up others' work so they can look good. In this case, Jenna deleted a very important file from the OP, about a project she had been working very hard on. I don't believe that it was accidental. I really don't. Especially when we later find out that she landed the promotion that both of them wanted. So I'm very sure Jenna did that on purpose so she could look good with the boss.

The worst part of all is that the manager didn't think about Jenna's behaviour whatsoever. Instead of finding out why she did it and why she has someone like that on her team, she wanted to find a solution for the problem as quickly as possible, since the very important meeting was the day after. I mean, I understand that first we need to fix the issue and later move on to the conflict of interest, but I'd never let that slip, and I'd have had Jenna interrogated. 

I'm sure that's the part that hurt the OP the most. Not feeling backed up in a situation like this. And, of course, I cannot imagine how she must have felt when she realized that Jenna got promoted. A promotion that the OP could have gotten if that presentation had gone well. That's just the most unfair thing ever.