Man was reloading ammunition inside Seffner home at time of explosion

The explosion that destroyed a Seffner home and injured two people was apparently caused by a man inside working with ammunition.

Firefighters say the man remains in critical condition but he was able to tell investigators that he was "actively reloading small arms ammunition" with at least six pounds of smokeless powder in the area when the explosion happened yesterday around 4:30 p.m.

Neighbors along King Charles Circle told FOX 13 they heard a loud boom and felt their homes shake. They also said they saw a thick plume of smoke. Many of them rushed over to try to help or to all 911. 

Half of the home was reduced to rubble by the blast. The garage door was blown all the way across the street, and at least one vehicle inside was damaged. Soon, witnesses realized people were still inside the destroyed home.

"When I came around the corner, my mouth dropped," neighbor Michael Bristow told FOX 13. "We're seeing everybody running and stuff like that. And then all you see is like the pieces of the house, like everywhere, like falling apart and you see water squirting everywhere."

An eyewitness said some heroic neighbors, along with deputies, pulled the woman and man from the wreckage.

"She was just hysterical and really panicking. The gentleman, however, looked like to me he sustained more injuries because he was covered in blood. And he was kind of dazed a little bit," Bristow recalled. "The house can be replaced, but lives cannot. So thank God and I pray that they'll be OK."

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Hillsborough County Fire Rescue says the woman has been treated and released from the hospital; the man remains in critical but stable condition.

Investigators say there’s no evidence suggesting criminal charges would be necessary. They’ve turned the home back over to the homeowners, declaring it a total loss.