Claim: The 1971 Led Zeppelin European concert tour, which started on May 3 and concluded on July 5, 1971, was well known for its violent crowds particularly one which took place at the Vigorelli Velodrome in Milan on 5 July, where 15,000 people abandoned the concert grounds when tear-gas wielding riot police charged into the crowd.
Evidence: The tour commenced on 3 May and concluded on 5 July 1971. 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. This festival appearance in front of an audience of 15,000 people was abandoned when hundreds of tear-gas wielding riot police charged into the crowd.