Claim: The 1971 Led Zeppelin European concert tour was well known for its violent crowds particularly one which took place in Liverpool, England on 5 July, where 15,000 people abandoned the concert grounds when tear-gas wielding riot police charged into the crowd.
Evidence: Led Zeppelin's 1971 European Tour was a concert tour of Europe by the English rock band. Though being very short in duration, this concert tour was well known, primarily because of the extremely violent crowd disturbance which took place at the band's concert at the Vigorelli Velodrome in Milan on 5 July.