The explosion happened shortly before 8:30 a.m. in the unit block of Van Dyke Drive in New Castle City.
Tuesday is trash day in the neighborhood. Kendra Eggleston, who lives on Van Dyke Drive, had spent the weekend cleaning out the garage.
She threw most of it out, including a padlocked ammunition box she found under her late husband's workbench.
An electrician who lives across the street, 55-year-old William Hailey, asked Eggleston if he could have the ammunition box. When she agreed, Hailey took the box back over to his property and set it down on the tailgate of his pickup truck.
Hailey saw the box on the curb and asked if he could have it. He then carried it across the street and set it on the tailgate of his pickup truck where he apparently worked the lock off.
Eggleston says he took something from inside the box and tossed it in a nearby trash can. That's when it exploded.
Neighbor Steve Ballas told Action News, "I heard this big 'BOOM.' Sounded like a grenade, sounded like one of the boxes blew up. And all of a sudden I heard this, 'Help! Help!' And there was Bill. He was staggering across the yard."
Another neighbor, Brian Atkins, said, "I went running around the corner and found Bill laying in the middle of his yard. He was cut up pretty bad. He was alert and he was conscious."
Hailey was peppered by shrapnel and rushed to Christiana Hospital, where he's in serious condition.
Eggleston said her late husband served in Vietnam and apparently brought the ammo box home with him. They moved here 22 years ago.
Don died in 1999 and the box sat undisturbed under his work bench until this past weekend.
A 2-block area was evacuated for hours and the bomb squad from Dover Air Force Base responded to the scene.
Action News has learned the team found six pieces of unexploded ordnance. Three were still in the ammo box, three more had been blown out of the box.
All of the unexploded ammunition was secured and no further injuries reported.