PIERRE PART - A loud bang spooked residents in part of Assumption Parish on Monday night, prompting sheriff's deputies to investigate the cause of the explosion.

The sheriff's office said the sound was caused around 8 p.m. by a person detonating Tannerite, a small-scale explosive often used in target practice. A spokesperson for the department said they've determined who set off the explosive, but it is still investigating whether anything illegal happened. 

Tannerite can be legally purchased, but the nature of the investigation could change if it's determined other materials were used to strengthen the explosives.