A Random

SCIFI.radio story

Earth encounters a group of time-traveling tourists on a sightseeing trip to the past who are friendly but incomprehensible even though they can all do credible singing impressions of Ethel Merman and cannot be destroyed by the army, navy, air force, space force and/or marines , but scientists create a new weapon which turns them into weird rocks.
The End.and then they kill us all.
The End.