Shanna Hogan

The literary world was rocked this week by the death of Shanna Hogan, a popular true-crime author whose tome on the headline-grabbing Jodi Arias case made her a New York Times bestselling author.

Hogan, 38, died on Sept. 1 after she slipped, hit her head and became submerged in a pool at her Phoenix home while swimming with her 14-month-old son, Zander on Aug. 27, her friend and former colleague Kathleen "Katie" Mayer told PEOPLE on Tuesday.