Florida wildlife officials are investigating the death of a "very thin" whale that drew national media attention when he became beached on a sandbar in the city of Venice.

"The fact that it was this close to shore and this skinny, tells us something has been going on for a while," Gretchen Lovewell of Mote Marine Laboratory told WTVT.

Officials from the laboratory, the Venice police and the Sarasota County Sheriff's Office spent much of Sunday attempting to free the endangered marine mammal. 

He was first spotted around 8:30 a.m. on Sunday, 150 yards from the beach before moving to a closer sandbar, according to USA Today. The beach was closed off, on Sunday, while scientists attempted to give the whale a sedative - they'd reportedly intended to try again on Monday. 

The severely underweight whale was struggling to breathe before he died in the early hours of Monday morning.

As scientists work to determine the whale's exact cause of death, locals have been advised to avoid returning to the beach.

"Throughout that process, there will be a number of bodily fluids going out into the water, and we really want to encourage people to avoid the water. We are concerned about predations. So, for human safety, if people can avoid the water that would be great," Lovewell told WTVT. 

"We'll do a ton of measurements, we'll do a bunch of external photographs and then we'll actually start to go in systematically and do the necropsy."