The soldiers were relieved to find out it was a dud bomb.
Солдаты были рады узнать, что это была неразорвавшаяся бомба.
Definitions
A 'dud bomb' refers to an explosive device that fails to detonate as intended. In general usage, 'dud' means something that does not work or perform as expected, so a 'dud bomb' is a bomb that does not explode when it is supposed to.
