Alabama ? A day after reporting his four young children were missing, a shrimp fisherman broke down and confessed that he threw them off an 80-foot-high bridge to their deaths, authorities said Wednesday.

Lam Luong, 37, was charged with four counts of capital murder, and divers searched the murky waters for the bodies of the youngsters, who ranged in age from a few months to 3 years.

Luong had a drug habit and had argued with his wife, Ngoc Phan, before taking the children, said Phan’s brother-in-law, Kam Phengsisomboun.

Luong’s girlfriend, who was living in a hotel in nearby Gulfport, Miss., figured into the couple’s argument on Sunday and then on Monday morning, family members and police said.

Authorities said they believe Luong then drove Monday to the two-lane Dauphin Island bridge over the Intracoastal Waterway, stopped at the highest part of the span and threw the youngsters over the side.

Luong and his wife reported the children missing Monday. He initially told police that he had given the kids to his girlfriend and that she failed to return them, investigators and family members said.