ITV suffered an eleven-week industrial dispute in 1979, leading to the subsequent shutdown of almost all ITV broadcasts and productions. It began at London's Thames Television when electricians (EETPU members) refused to accept what they considered to be a derisory pay increase. Management attempted to operate a normal service but other transmission staff (ACTT members) refused to co-operate, pointing out that equipment and wiring turned on by non-EETPU members could be potentially dangerous. Thames management interpreted this as a walkout. When Thames' management consequently ordered the striking staff to "return or else" the broadcasting union the ACTT instructed members at thirteen other ITV stations to walk out in solidarity. The only company unaffected was Channel Television as the unions realised that industrial action there could lead to the station's closure as its small audience made it vulnerable to any loss of advertising revenue.