Divers working near the Bains des Pâquis made a strange discovery - a World War One shell.
Police quickly evacuated the area for about 45 minutes while a bomb disposal team examined the object.
The shell turned out to be empty, and no one was injured.
Experts say we should not be surprised. Thousands of tonnes of munitions were dumped in the lake after the war, right up to the 1960s.
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