Complex sentence: There have been reports of fatalities resulting from flower urchin envenomation in Japan, but it remains difficult to confirm if these incidents actually occurred since no documentation or details of the deaths have been uncovered so far.
Split into simpler sentences: There have been reports of fatalities resulting from flower urchin envenomation in Japan. But it remains difficult to confirm if these incidents actually occurred since no documentation or details of the deaths have been uncovered so far.