Notwithstanding Section 103465, upon the filing of a petition for a determination of the fact of death in the event of a mass fatalities incident, the clerk shall set a hearing no later than 15 days from the date the petition was filed. The petitioner shall make a reasonable effort to provide notice of the hearing to the known heirs of the deceased up to the second degree of relationship. Failure to provide the notice specified in this section shall not invalidate the judicial proceedings regarding the determination of the fact of death.