BRADENTON, Fla. (WFLA/AP) –  Snooty, the world’s oldest known manatee, has died just one day after celebrating his 69th birthday.

The South Florida Museum made the devastating announcement Sunday afternoon on Facebook.

On Monday, the museum announced that the cause of Snooty’s death was drowning.

“Snooty was found in an underwater area only used to access plumbing for the exhibit life support system. Early indications are that an access panel door that is normally bolted shut had somehow been knocked loose and that Snooty was able to swim in,” the museum said in a press release. “Snooty’s habitat undergoes a daily visual inspection and there were no indications the previous day that there was anything amiss.”

“Our initial investigation indicates that Snooty’s death was a heartbreaking accident and we’re all quite devastated about his passing,” Museum CEO Brynne Anne Besio said in a release. “We’re reviewing what happened and will be conducting a full investigation into the circumstances.”

The other three manatees undergoing rehabilitation in Snooty’s habitat are all fine.

The museum is set to reopen to the public on Tuesday. Officials say grief counselors will be there to help the staff.

For years, Snooty held the distinction of the museum’s resident manatee.  When asked if the museum had plans to have another resident manatee, ‎Provost & COO Jeff Rodgers said “We are still processing Snooty’s loss right now, we don’t know if we will have another resident manatee.”