By Paul Kurtz

By Paul Kurtz

PHILADELPHIA (CBS) — There’s no doubt that a huge crowd attended Sunday’s Papal Mass along the Ben Franklin Parkway, but city officials have yet to release a formal estimate. A crowd safety expert was able to give a partial crowd estimate.

Professor G. Keith Still of Manchester Metropolitan University in England did not have much to go on; a single newspaper photo of a chunk of the parkway and the Art Museum taken from the top of a nearby high-rise, but it was enough for him to estimate the crowd size in that space at between 80,000 and 140,000.


“I made the estimate based on the reasonable information that was available, based on observable crowd density and known crowd density based on those types of events.”

Still says there is a process involved with determining crowd size that most often takes place in the planning stage of a big event.

“What is the safe capacity? How do we get people in and out of these areas quickly, efficiently and safely and if anything goes wrong how do we manage any emergency situation in that environment?”

Still’s estimate may conflict with others but he says that’s no surprise.

“The numbers that the planners use, the numbers that the press might report and then the numbers the police might report because they have to justify resources.”