The Sunken Grim Reaper in Training

Scarlet Jay White's life has been cut short at the age of 15. While on a bus on the way to school tragedy strikes in the form of a Earthquake, and her bus sinks to the bottom of the Bay. Now dead, isn't she supposed to float up to heaven, be told if she is or isn't acceptable for eternal happiness, and then chill out?
No. Because Scarlet died when she had barely begun to live. She wasn't even supposed to die! Now being trained at the 'School for the Pre - Maturely Dead', Scarlet will learn how to become one of the millions of Grim Reapers until she has reaped 115 souls, saved 19 lost souls, and figured out why she died at the wrong time.