This case study examines a variety of biological factors that may have been involved in the 2013 dolphin "unusual mortality event" (UME) on the East Coast of the United States. The story follows a news reporter and four different scientists who are preparing their notes for speaking at a public hearing about the dolphin die-off event. After reading the story, students assume the roles of these scientists and use the jigsaw method to gather, analyze, and share information. Due to the interdisciplinary nature of environmental toxicology, this case study exposes students to four main topics: ecology of ecosystems, endocrine system/chemical messaging, immune system function, and virus biology. The case also emphasizes the importance of considering an issue from multiple viewpoints since even scientists can sometimes be biased to their field of interest when proposing explanatory hypotheses. This case was originally designed for an undergraduate introductory biology or environmental science course. With some adaptation it may also be suitable for an advanced high school biology class.