NYC Department of Buildings has reported within a June 6, 2011 Freedom of Information response, that no records could be located regarding the request for information pertaining to the massive elevator modernization project underway at WTC

On Sept. 11, the mechanics left on their own, without instructions from police or fire officials. ACE Elevator supervisors say this was consistent with the emergency plan. All the mechanics survived.
----------------------------------
THERMITE CUTTING STEEL - VALIDATED - EXPERIMENTALLY DEMONSTRATED