When the paravane contacted the submerged U-23 , it blew debris into the air , sinking the submarine with all hands .
U-23 came under attack by the Italian torpedo boat Airone which first tried to ram the U-boat , and then deployed an explosive paravane .
When the paravane contacted the submerged U-23 , Airone blew debris into the air , sinking the submarine with all hands .
U-23 came under attack by the Italian torpedo boat Airone which first tried to ram the U-boat , and then deployed an explosive paravane .