I think we've got most of the story here, but not quite all of it. This info is excerpted from Snopes.com.
In February 1999, a park custodian at Walt Disney World's Magic Kingdom was killed when the skyway started up unexpectedly while he was cleaning one of its platforms. Raymond Barlow, 65, was sweeping off a narrow skyway platform inaccessible to park guests an hour after the park's 9:00 A.M. opening when other cast members, unaware of his presence, started up the ride. Barlow, startled by the approaching gondola, grabbed onto it and tried to climb inside; he fell 40 feet into a flower bed, hitting a tree on the way down, and died.
The Occupational Safety and Health Administration later ruled that the area in which Barlow had been working violated federal safety codes and fined Walt Disney World $4,500 for a "serious" violation of safety standards. Several months later, in November 1999, the Magic Kingdom's skyway was permanently closed.
As was the case with the closing of the
Disneyland skyway in 1994, the decision to close the attraction was based on factors other than its being involved in a recent accidental death. The Skyway was not dismantled out of a fear of similar incidents, but for a variety of economic factors, including the attraction's age and carrying capacity, staffing requirements, maintenance costs, and the expense required to upgrade the Skyway to conform to newer safety and access standards.
The full Snopes.com account can be read here:
http://www.snopes.com/disney/parks/skyway.htm