Rescue crews were searching on Thursday for seven people still missing days after an explosion at a fireworks warehouse in Northern California shook a tiny farming community and forced the cancellation of nearby July Fourth celebrations.

The parents of three brothers — 18-year-old Jesus Ramos, 22-year-old Johny Ramos and 28-year-old Junior Melendez — faced the danger head-on, desperate to find their sons after the fireworks facility they worked at exploded.

The company indicated that multiple people died in the incident three days before the Fourth of July, but officials have not issued a determination.