‘As a father, as a grandfather, we're going to hope for the best in these circumstances,’ Orange County Sheriff Jerry Demings said at a late Tuesday press conference.
‘But based on my 35 years of law enforcement experience, we know we have some challenges ahead of us.’
Demings said that a family of five from the midwestern state of Nebraska was relaxing on the shore of a man-made lake at the upscale Disney resort when an alligator emerged and snatched the boy at around 9:00 pm Tuesday (0100 GMT Wednesday).
The father, who Demings did not name, entered the water but failed to rescue his son from the animal's jaws.
Demings said that a team of some 50 people had been deployed to search for the child.
Rescuers used sonar and lit the area with bright lights overnight as a helicopter hovered overhead. Firefighters stood on the water's edge with infrared cameras scanning the water for the child.
An alligator trapper was on standby along with a team of divers waiting for daybreak to enter the water.
‘Everyone here at the Walt Disney World Resort is devastated by this tragic accident,’ a Disney official said at the press conference.
Alligators are common in Florida, but rarely attack humans.