Four years later, there are a host of unanswered questions about the events of 9/11, including the unexplained and unprecedented architectural collapses of three office towers, and the extent of toxicity in the air of Lower Manhattan.
"Why Did WTC 7 Fall? [WTC 7]was...probably the first steel skyscraper anywhere to collapse solely because of fire. We still don't know why...according to FEMA's report on the collapse [the fire hypothesis] "has only a low probability of occurrence."
"How did the twin towers fall? Many FDNY personnel who saw the south tower collapse reported explosions at the lower levels as the top began collapsing. These reports, as well as "squibs" of smoke seen on video of the collapses, have led to theories that the towers were brought down in controlled explosions."
"Conspiracy theorists aren't the only ones who dispute [the official]version: Some fire scientists also take issue with [it]...And the point isn't just historical. The lessons learned from the WTC collapse will inform decisions about the safety of other modern office towers."
FULL STORY: Open and Shut
Planetizen Federal Action Tracker
A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.
Canada vs. Kamala: Whose Liberal Housing Platform Comes Out on Top?
As Canada votes for a new Prime Minister, what can America learn from the leading liberal candidate of its neighbor to the north?
The Five Most-Changed American Cities
A ranking of population change, home values, and jobs highlights the nation’s most dynamic and most stagnant regions.
Rethinking Computing: Researchers Tackle AI’s Energy Demands
USC researchers are reimagining how AI systems are trained and powered — through smarter algorithms, innovative hardware, and brain-inspired designs — to dramatically reduce computing’s energy footprint.
Amazon-Owned Robotaxis to Begin Testing in LA
Los Angeles will become the sixth city where Zoox is testing its autonomous vehicle technology.
New York MTA Says No More Borrowing, Will Cut Costs Instead
The agency says it won’t take out any new loans to finance its planned improvements and is finding other ways to cut costs.
Urban Design for Planners 1: Software Tools
This six-course series explores essential urban design concepts using open source software and equips planners with the tools they need to participate fully in the urban design process.
Planning for Universal Design
Learn the tools for implementing Universal Design in planning regulations.
New York City School Construction Authority
Village of Glen Ellyn
Central Transportation Planning Staff/Boston Region MPO
Institute for Housing and Urban Development Studies (IHS)
City of Grandview
Harvard GSD Executive Education
Regional Transportation Commission of Southern Nevada
Toledo-Lucas County Plan Commissions