The gorillas are one of the favorite parts of the Saint Louis Zoo for many. That's why it was sad to hear the news shared by the news from one of their gorillas who has been a crowd favorite.

The Saint Louis Zoo shared this somber update on their Facebook page today.

In case you can't read the small print, "Little Joe" passed away in his sleep at the Saint Louis Zoo Saturday, May 4 after treatment for heart disease. The zoo believes a heart attack was the cause.

As this is a developing story, it will be updated once new information is released about the passing of this beloved Saint Louis Zoo gorilla.

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