TANGERANG, Indonesia — At the age of 14, Surnah was done with school, and a month ago she took a full-time job packaging fireworks at a new factory near her home. On a good day, she could make about $3.80.

On Thursday, she died along with 47 other workers when a welder’s spark ignited a fire at the factory, the police say, causing two explosions.

“I am feeling very lost,” said her mother, Suti, 29, who, like many Indonesians, goes by one name. “She was my only child.”

Surnah was one of at least three underage workers at the factory, their family members said Sunday. All three were 14-year-old girls who stopped attending school after the sixth grade because their families could not afford the costs.