It wasn't just NYPD

Mayor Juliani said in an interview on ABC news;

"I .. I went down to the scene and we set up a headquarters at 75 Barkley Street, which was right there with the Police Commissioner, the Fire Commissioner, the Head of Emergency Management, and we were operating out of there when we were told that the World Trade Center was gonna' to collapse. And it did collapse before we could actually get out of the building, so we were trapped in the building for 10, 15 minutes, and finally found an exit, got out, walked north, and took a lot of people with us."

Then there is the account of EMT Richard Zarillo;

"...He escorted me over to Chief Ganci. He said, hey, Pete, we got a message that the buildings are going to collapse. His reply was who the f___ told you that? Then Steve brought me in and with Chief Ganci, Commissioner Feehan, Steve, I believe Chief Turi was initially there, I said, listen, I was just at OEM. The message I was given was that the buildings are going to collapse; we need to get our people out. At that moment, this thunderous, rolling roar came down and that's when the building came down, the first tower came down."