Air sirens went off as soon as dummy bombs were ‘detonated’ at Cross Maidan near Bombay Hospital in Marine Lines on Wednesday evening. The well-planned exercise was carried out as part of the nationwide drill, Operation Abhyas, with multiple emergency response teams being mobilised to simulate a coordinated response to a terrorist bombing scenario in the wake of the terror attack in Pahalgam, Jammu and Kashmir. The drill sought to help the authorities assess the preparedness of local emergency services in a densely populated urban setting.