LIHUE, Hawaii (AP) — Wildlife officials are still unsure what caused seven pilot whales to beach themselves along a Kauai beach.

The whales showed up at Kalapaki Beach last Friday. Of the seven, two died before they could be pushed back into the ocean. The other five went back into the water, but three more whale bodies later washed ashore.

Personnel from the University of Hawaii, NOAA Fisheries, Hawaii Department of Land and Natural Resources, and volunteers worked together to conduct a necropsy, or post-mortem exam, on the five dead whales.

Preliminary results showed no obvious cause of death. Samples were taken and sent out to labs for further analysis.

One thing they're checking is to see if any of the rat poison dropped on Lehua Island made it into their systems.