A pod of 17 whales have died after beaching themselves on the Florida coast.
A total of 22 short-finned pilot whales came ashore at Avalon Beach State Park on Saturday morning.
Conservation officials and concerned members of the public managed to save five calves and juvenile whales.
Despite a day-long rescue effort the rest died of natural causes or were euthanized.
The creatures, which are the biggest in the dolphin family after killer whales, came ashore near Fort Pierce, on Florida's south-central Atlantic coast.
The US National Park Service, Florida Fish and Wildlife and the National Oceanic and Atmospheric Administration (NOAA) participated in the rescue effort.
Previous incidents have been blamed on infestations of parasites that affect the whales' brains and their ability to stay on course.
They normally stick to deep waters, where they feed on a diet that includes squid and octopus.
The cause of Saturday's mass beaching was not immediately clear, but Allison Garrett of NOAA said necropsies might help explain what drove the mammals ashore.
"These are very social animals," Ms Garrett said.
"If one of them is sick and goes and strands, the others will stay with it, they won't leave."
Male pilot whales, which are normally dark black and larger than their female counterparts, can grow to about 20ft and tip the scales at as much as three tons.