-- "A 19-year-old with North Macedonian roots, and a 17-year-old of Turkish and Croatian origin were arrested for plotting an ISIS-style terror attack at the Austrian concerts They had planned to drive a bomb-filled car into the crowd to kill as many as possible and had reportedly just been hired by the venue to work security." --And...
-- "The pair had also made contact with others who were apparently aware of the terror plot plans.". --
Sounds like somebody gave it up to the authorities.
Meanwhile... back in Jolly old England.