Authorities said the explosive device was safely removed from the water and detonated on land away from the dam near Mobile. 

No injuries were reported.

A suspect has not yet been named.

Investigators have not determined how the device ended up at the bottom of the dam, though bomb experts told 1819News it appeared to have been intentionally built and placed there.

“Our top priority is keeping your drinking water safe,” said Bud McCrory, director of the Mobile Area Water and Sewer System (MAWSS), which hired the divers conducting maintenance work at the reservoir.

“This is an unprecedented threat, and we are fortunate that this device was discovered before it could cause serious damage to our water supply or harm to individuals,” McCrory said.

The Converse Reservoir dam and the Big Creek Lake water supply are considered federally designated critical infrastructure, prompting officials to refer the case to the Department of Homeland Security for more investigation.