NAPLES, Fla. -

Two pilot whales died and a third would be euthanized after roughly four dozen whales swam into shallow waters off southwest Florida on Monday, wildlife officials said.

A handful of the whales stranded near shore in Lee County, while more than a dozen others swam nearby, said Kim Amendola of the National Oceanic and Atmospheric Administration's Fisheries Service.

An additional 12 whales were spotted farther offshore earlier in the morning.

Necropsies would be performed on the three beached whales, said NOAA regional stranding coordinator Blair Mase.

The remaining whales were listless and emaciated, and many wouldn't react if a boat approached them, Mase said.

"They all look in really bad shape," she said. She expected that more whales could die by Tuesday morning.

Meanwhile, roughly two dozen other pilot whales were being monitored off Collier County. Those whales were the same pod that swam into shallow waters off Naples on Sunday, Amendola said. A few temporarily beached themselves Sunday before swimming out with the tides.

They also seemed to be in poor shape.

"They're definitely out of their home range, and they look like they've been out of their home range for quite a while," Mase said.

Pilot whales typically swim in deeper waters farther offshore. It wasn't immediately clear what caused the whales to swim so close to land.

The pilot whale is a common species involved in mass strandings. In early December, more than 50 pilot whales stranded in Everglades National Park. Seven died and four were euthanized before the rest apparently swam back into deeper waters.