NEW YORK -- Dwight Howard and his teammates received an unusual text message Tuesday afternoon: Report to the team bus at the usual time, but don't bother getting ready for that night's game at Madison Square Garden. There won't be one.

Fearing that asbestos had fallen from the rafters at the building known as the World's Most Famous Arena, the New York Knicks postponed their game against the Orlando Magic.

A spokesman for the New York City Department of Environmental Protection said two air-monitoring systems detected potentially dangerous fibers, but secondary testing by an independent contractor showed the fibers were not asbestos.

The Knicks released a statement saying maintenance was being performed following Monday's New York Rangers game, which included "cleaning asbestos-related materials in the attic above the ceiling." Some debris fell into the arena.

After consulting with the NBA, the Knicks decided to postpone the game for safety reasons. They said they will work with experts to determine when the arena can reopen, but a Garden spokesman would not speculate on whether the building would be deemed safe in time for the Knicks' next home game, Friday night against the Washingon Wizards.

"As the safety of our customers and employees are our top priority, we will not reopen the Garden until we are absolutely assured the arena is safe," the team said in a statement.

No makeup date for the Magic-Knicks game has been set. MSG said it would announce information about future events once details are finalized.

New York City Department of Environmental Protection spokesman Farrell Sklerov described the debris as "dustlike" and said it was dislodged as part of cleaning work unrelated to the extensive construction renovations taking place at MSG.

"There are air monitoring stations set up throughout building, and two of them in the seating area indicated slightly elevated levels of fibers that could potentially contain asbestos. They did further secondary testing with equipment that can differentiate those fibers, and those tests showed that no asbestos was released and everything is safe," Sklerov said.