Rihanna shared this photo on Instagram with the caption "😢 🇬🇧 🙏🏿."
Paris Hilton also shared a photo with #PrayForLondon.
And Cara Delevigne said, "My heart is with you London. Please can everyone stay safe. This is beyond tragic but we must stand together and not let this break us."
Dwayne Johnson said, "Sending prayers, love, strength and resiliency to the UK."