Saturday’s crush disaster in Seoul, which killed 154 people including two Japanese, has surely left many people in Japan wondering: just how safe are crowds in Japan?

The police and government significantly stepped up crowd control measures in the wake of a pedestrian crush after a fireworks show in 2001 in Akashi, Hyogo Prefecture, which left 11 people dead and 247 injured, experts say. That disaster — considered by police to be a “disgrace” — led to the creation of a variety of police manuals on congestion control, and has made it standard practice for organizers of major events such as fireworks festivals and sports games to prepare detailed security plans and consult with local police beforehand.

But spontaneous large-scale gatherings for which there are no clear organizers responsible for crowd safety — such as with Saturday's Halloween celebrations in the South Korean capital's Itaewon district — are harder to control, and Japan isn’t immune from the risk of deadly crushes, experts say.