A 44-year-old man visiting Walt Disney World with his family died Tuesday after apparently suffering a heart attack on the Expedition Everest roller coaster in Animal Kingdom — and despite company efforts to distribute portable heart defibrillators throughout the resort, none was immediately available for him.

The death was the first associated with the nearly 2-year-old ride and the fourth this year connected with a Disney World attraction.

Jeffery Chalmers Reeb, of Navarre, Fla., was unconscious and unresponsive when his ride vehicle pulled into the unloading area about 11:25 a.m. Tuesday, though investigators said a camera at the attraction showed him conscious less than a minute before the ride ended.

Reeb was given cardiopulmonary resuscitation by a Disney employee at the scene and another visitor who was a registered nurse. Reedy Creek Emergency Services paramedics reached him in about five minutes.

At about that time, a 911 caller advised the Reedy Creek dispatcher that there was no portable defibrillator around.

Reedy Creek Assistant Fire Chief Bo Jones said it would be impossible to know whether a readily available portable defibrillator would have made any difference. He said it would not have made any difference to Reedy Creek’s paramedics, who carry their own.

The man had no pulse when paramedics arrived, Jones said. There was no apparent trauma and “no obvious signs of any cause,” he said. Reedy Creek transported him to Florida Hospital Celebration Health, where he was pronounced dead.

Declaring that portable heart defibrillators may have saved as many as 40 lives at Disneyland and Disney World or on Disney Cruise Line ships since 650 of them were installed in 2003, the Walt Disney Co. announced just last month that it intends to install 250 more on its properties, including another 200 at Disney World.

The company also has trained thousands of employees to use them.

There reportedly were at least two in Animal Kingdom on Tuesday, including one at a first-aid station on Discovery Island, a couple hundred yards away from the Everest ride, and one on a mobile cart.

Reeb’s death is not the first associated with an apparent heart attack at a Disney theme-park location lacking a defibrillator since the company began its program. In 2005, a 4-year-old boy with an undetected heart disease died of a heart attack after riding the Mission: Space ride at Epcot. The family sued, and one of the allegations was that Disney had not placed a defibrillator near enough to that ride. Disney and the family eventually settled the lawsuit for undisclosed terms.

The Orange County Sheriff’s Office reported that Reeb appeared to be conscious about 50 seconds before the ride ended because his photograph was taken as the coaster progressed toward the unloading area. The Sheriff’s Office also said investigators think the ride was operating properly.

The Sheriff’s Office said Reeb was visiting Disney World with family members. Its report also indicated that no one witnessed the cardiac arrest.

A Disney spokeswoman said the company has offered Reeb’s family “our deepest sympathies” and assistance.