Utah fire officials set off a stash of "ancient dynamite" discovered in a residence on Wednesday, prompting nearby residents to evacuate overnight before the controlled explosion could be completed.

A woman found the explosives in her home near 6200 South and 2300 East in Holladay. She was cleaning after recently losing her husband and discovered a large amount of very old dynamite had apparently been passed from generation to generation.

At a press conference on Tuesday, Unified Fire Authority Capt. Tony Barker said the local health department and Environmental Protection Agency initially responded to investigate a report of hazardous materials, and they called for the UFA to dispatch a bomb squad and hazmat teams.

 Barker described the dynamite as "ancient," and said there was "a lot" of it. "It's pretty impressive in scope," he said.

"The information we received is the dynamite was passed down from generation to generation, so how old it is, we actually do not know," he said.

Homes within 1,500 feet were evacuated starting at around midnight, and a shelter-in-place order was issued for the surrounding area as officials prepared for a controlled detonation.

Two loud explosions were seen at around 4 a.m. Wednesday, and could be heard from miles away.

Speaking to press on Wednesday, UFA Assistant Chief Dustin Dern said the explosion resulted in a fire that crews were on hand to extinguish. There was no damage to surrounding structures, but the home the dynamite was found inside was a total loss.

--with reporting by TMX