Rescue crews trying to help a blue whale trailing about 400 feet of fishing line off the coast of San Pedro, Calif. lost track of the enormous creature on the second day of the operation. The whale was spotted on Friday by a group out on a whale watching expedition, according to The Inquisitr,  A Los Angeles county sheriff's helicopter joined boats, planes and helicopters in the search for the 80 foot mammal.

"My gut feeling is it went south, but its actual path remained a mystery," said Peter Wallerstein, president of the nonprofit group Marine Animal Rescue. "We're having to look all over it."

Rescue crews worked into the night Friday as they attempted to free the giant mammal, but they eventually lost track of it, The Los Angeles Times reported. "They were going to come in but decided to go back out and try to cut off as much line as they can," said Justin Viezbicke, California Stranding Network coordinator for the National Oceanic and Atmospheric Administration.

"The seas were rough," Wallerstein said while describing the rescue efforts. "It was hard to get to the whale, but we were able to attach a buoy to the whale. We didn't do any cutting. The whale didn't surface enough."

The buoy was to be used as a marker, but the elusive blue whale was nowhere to be found, despite an all-out ground, sea and air search.

The blue whale, Earth's largest animal, is an endangered species, according to WTVR. The mammal is found off California, Chile and the Coral Triangle near Indonesia.