Visitors to Antietam battlefield in 1862 took unexploded shells home as souvenirs. The results were disastrous, and often deadly.
Deadly Souvenirs – Unexploded Shells From Antietam Proved To Be Dangerous Keepsakes

Visitors to Antietam battlefield in 1862 took unexploded shells home as souvenirs. The results were disastrous, and often deadly.