The attack, though unsuccessful, delivered a seismic shock to patients who feared for the safety of their embryos. But a firefighter’s risky plan averted disaster.

Investigators are combing through the writings of a 25-year-old man believed responsible for bombing a Palm Springs fertility clinic.

Authorities told The Times they are looking into videos, audio files and other postings attributed to Guy Bartkus as they try to determine the attack motive.