NOAA ended its search for a 3-year-old Orca on Thursday after the emaciated killer whale had not been seen in a week.

The whale, named J50 or Scarlet, was last seen on September 7 “lagging a half-mile to a mile behind the rest of her family group,” according to a September 8 NOAA release. She appeared in dire straits; biologist Joe Gaydos called her the “thinnest killer whale” he’d seen.

A NOAA press release Friday stated that the federal agency decided to conclude its search.

“After dedicated search efforts for J50 over the last two days, J50 was still unaccounted for,” the statement reads. “The team ended its active search last night.”

Nonprofits and groups affiliated with the West Coast Marine Mammal Stranding Network remain on alert, NOAA said.

“We remain grateful to our many partners and everyone who has lent support to the response and search,” the press release states.

Southern resident killer whales, seen frequently off the coasts of Washington and British Columbia, are critically endangered, according to NOAA. With the loss of J50 they will number just 74 animals.

The exact cause of J50’s illness is not known. The whale’s death would be the second among southern resident killer whales this summer; in July, an emaciated newborn calf of 20-year-old female J35, or Tahlequah, died 30 minutes after birth.