One man lost at least part of his hand and another man was injured in a July 4th fireworks accident near the Potawatomi Zoo on Monday.

A 25-year-old man and a 21-year-old man were working at the zoo as part of an Indiana Department of Correction work release program when they found a firework they thought was a smoke bomb, WSBT reported.

The 25-year-old man lit the firework and it blew up in his hand. Shrapnel hit the younger man in the back.

Both men were rushed to Memorial Hospital of South Bend, where the 25-year-old man underwent surgery and the 21-year-old man was treated and released.

The men are from Adams and Grant counties. They were working at the zoo to prepare for full-time jobs when they are released from prison later this year, WSBT reported.

The DOC allows prisoners in work release to smoke tobacco, so they were allowed to have a lighter or matches.