As an extraordinary two-week quarantine of a cruise ship ends Wednesday in Japan, many scientists say it was a failed experiment: The ship seemed to become an incubator for a new virus instead of an isolation facility meant to prevent the worsening of an outbreak.

So what exactly went wrong on the ship? While no one is able to offer a definitive answer, experts and non-experts alike have their views to share. 

Read more: What exactly went wrong on Diamond Princess?