I recently started looking into the MBA process about a year ago. For some background, I majored in Finance in undergrad from a strong public institution in the North East with a 3.23 GPA (low Freshman Year; Averaged a ~3.6 across my final 3 years). 760 GMAT.
About 1.5 years after graduation (3 years ago), I was bored and decided I wanted to take two courses (Calc 1 and Statistics) at a local community college for fun. I did not have the option to audit these classes from what I remember. I was honestly just looking to get back into a classroom setting (feeling a bit nostalgic) and wanted do something stimulating. I had no intention of doing anything with these classes (i.e. use them to advance myself in my career or pursue another degree) and didn't even have graduate school on my radar. The reason I'm posting is that every school I'm looking at, except one, requires you to report transcripts/grades from all courses regardless if they counted towards your degree.
Long story short, about 2 months in I took on more responsibility at work and unfortunately ended up losing a close family member around this time, which made life incrementally tougher for a few weeks. I stopped attending the classes (as I said, these were only for "fun" in my mind) so that I could prioritize work and my personal life. Unfortunately, the withdrawal period had passed as well. I stopped showing up and didn't take the last tests/finals, and probably received a failing grade as a result (the school sent me a transcript, I never opened it). I had no idea this would be something I would have to report in the future on a graduate application, or I never would've taken these classes.
I realize there's an addendum to explain certain situations like this, but is this honestly an acceptable excuse? In addition, I'm taking Business Calculus and a Statistics course through the UCLA Extension program with the goal of getting an A in each of these to offset my previous performance and show I can perform in an academic setting. Assuming I do get an A in both, combined with the explanation above, how negative of an impact would this likely have on my application along with my lowish GPA from UG? I'm looking at 2 Top 10 and a few Top 15/25 programs.