Today's blast of the former St. Francis Central Hospital has been moved back from this morning to this afternoon.

That means the tough old building, which survived a previous effort to take it down, will survive for at least a few more hours.

The hospital and several other structures have to come down to make way for construction of the $290 million arena going up across Centre Avenue from Mellon Arena.

The implosion had been scheduled for 7 a.m. today. That was until the Pittsburgh-Allegheny County Sports & Exhibition Authority met yesterday with the demolition contractor, Homrich Inc. of Carleton, Mich., and the implosion subcontractor, Dykon Explosive Demolition Corp. of Tulsa, Okla.

Together, they viewed a virtual computer simulation of the event that was prepared by Applied Science International of Raleigh, N.C.

Among their concerns were weather forecasts for today that call for low cloud cover during the early morning.

The event has been moved to its backup time, between 2 and 2:30 p.m.

An attempt last month to take down the 10-story, 350,000-square-foot building using a technique called "controlled collapse" failed, prompting the contractor to decide on an explosives-triggered implosion.

"Our consultants agreed this was the safest, quickest way, using the best technology, to bring the building down," Doug Straley, the sports authority's project executive, said earlier this month.

Vehicle and pedestrian traffic will be restricted around the blast site for at least an hour before and 30 minutes after the implosion.

The restrictions will form a safe zone of about a dozen blocks around the site. It is bounded by Crawford and Pride streets to the east, Fifth Avenue to the south, Washington Place to the west and Bedford Avenue to the North.

The contractors and the authority recommend that residents of the Washington Plaza apartments and the Epiphany Church Rectory remain inside those buildings, which flank the hospital.

Parking will be prohibited anywhere in the safe zone, including the Mellon Arena lots, beginning at 2 a.m. today. Any vehicles still there after 2 a.m. will be towed.

A public viewing area will be arranged at the northern end of the Melody Tent parking lot, while media cameras will be directed to a reserved location on Crawford Street between Wylie and Bedford avenues.

Sometime after 3 p.m. the Mellon Arena box office, Team Store and parking lots will open for the Penguins game against the New Jersey Devils at 7:30 p.m.