are these fish tropical????

[SpongeBobTrianglePants]

my neighbour brought 3 neon tetras as he already had 5 and wanted to make them more secure, and he also brought 2 angel fish, he has just checked his water, and also the ideal temperatures, but they all died, even the 5 tetras he already had!!!!!!!! WHY??????

[Cheese]

yes these fish are all tropical, most likely they died from some kind of illness the new fish were carrying that why you have to isolate new fish for a couple of weeks, then again this is just a possibility.like the answer above said it could be that he added to many fish at once, also a possibility but for your question yes they are tropical.