At least 19 people were killed and 50 others injured in the blast at an Ariana Grande concert - which witnesses are claiming was caused by a 'nail bomb'. Newly released mobile phone footage shows panic spread across the crowd, as one terrified girl screams "oh my God" and others are seen running for their lives. The lights had just gone up and people were leaving the arena when a loud bang is heard. Fans are then seen running back into the concert hall screaming and frantically tearing through the stands.