Taylor Swift on Wednesday publicly addressed the three concerts that were canceled in Vienna after authorities said they foiled a planned terrorist attack, saying that having to call off the performances was “devastating.”

“The reason for the cancellations filled me with a new sense of fear, and a tremendous amount of guilt because so many people had planned on coming to those shows,” Swift wrote on Instagram following the conclusion of the European leg of her Eras Tour. “But I was also so grateful to the authorities because thanks to them, we were grieving concerts and not lives.”

Three sold-out shows at Vienna’s Ernst Happel Stadium were abruptly canceled earlier this month following the arrest of two teenagers who were allegedly planning a terrorist attack outside the venue, according to Austrian authorities. A third teenager was arrested a few days later in connection with the alleged plot.

Austrian authorities said a 17-year-old Austrian citizen with Turkish and Croatian roots and a 19-year-old Austrian citizen had planned to kill people outside the venue using knives or self-made explosives. While the alleged plot was foiled a day before the first of the three shows was scheduled, all three were called off.

Authorities said the plot appeared to have been inspired by ISIS and Al Qaeda. Investigators said they found bomb-making materials at one of the suspects’ homes. ISIS and Al Qaeda material were also allegedly found at the home of one of the suspects. 

“I was heartened by the love and unity I saw in the fans who banded together,” Swift wrote Wednesday. “I decided that all of my energy had to go toward helping to protect the nearly half a million people I had coming to see the shows in London. My team and I worked hand in hand with stadium staff and British authorities every day in pursuit of that goal, and I want to thank them for everything they did for us.”

The tour resumed last week in London, where Swift played five sold-out shows at Wembley Stadium, but with added security measures. Of note, fans were not allowed to gather outside the venue prior to the show, as they had done at previous stops throughout the tour.

“My priority was finishing our European tour safely, and it is with great relief that I can say we did that,” Swift wrote.