Satyan from nearby Kazhakootam, who was undergoing treatment for injuries suffered in Sunday's accident, died at the Thiruvananthapuram Medical College Hospital (TMCH), an official release said.
He was in a critical condition and had been on ventilator support before the end came this morning.
The condition of 26 other injured persons, including seven in TMCH, continues to be serious. Around 350 persons were undergoing treatment at various hospitals.
A total of 1,039 persons have been treated as outpatient in various hospitals in Kollam and Thiruvananthapuram, according to Chief Minister Oommen Chandy.
The ghastly mishap occurred when sparks from a firework fell on a storehouse stocked with crackers, triggering powerful explosions.
Last Updated 31, Mar 2018, 6:38 PM