Researchers now know more about the 10 Pygmy Killer Whales that were stranded in Kihei on Maui last month. A team of doctors from the University of Hawaii performed a necropsy on August 29, that's like an autopsy for animals. 

"We determined other animals that we necropsy are an immature female, an immature male, a lactating female and a pregnant female," Kristi West, Hawaii Institute of Marine Biology, University of Hawaii, said.  

Four of the 10 were euthanized and had lung abnormalities. Another calf that died outside of that group suffered pneumonia. 

"It's really important to understand that it's something that we take very seriously. It's with a heavy heart we have to do this," Gregg Levine, NOAA Contract Veterinarian, said. 

"We're not euthanizing the whales just to collect samples. We're euthanizing after a lot of consideration. We're making that decision based on animal welfare and public safety and human safety," David Schofield, NOAA Regional Marine Mammal Stranding Response, said. 

They do have a theory on why the mammals would go near shore when they usually live in waters at least 1,500 feet deep. 

"Animals would run ashore to shallower water to support themselves to breathe by beaching themselves. In shallow water, there's less chance of shark predation," Schofield said.

Volunteers and experts continue to monitor the original stranding site at Sugar Beach in Kihei to make sure others don't end up in the same situation. 

"If they should restrain, we will do the same type of thing. Assess to see which animals maybe healthy enough to go offshore. In the unfortunate case, we might have to euthanize," Schofield said. 

Scientists say the next step to figure out what happened: genetic and disease testing. They say that could take months, even years.