[AF] The SF Overpass

[Phil Alexander]

On 2 May 2007 at 8:17, Fee Lee wrote:

 > I thought only one tower only had the Asbesos coating partial up the
 > tower and some other type of coating the rest of the way.  The tower
 > that was built first had Asbesos all the way up to the top.  The main
 > reason that the coatings failed was that the planes hit the towers
 > with such force, the coatings were knocked off the steel beams.
 >                                            Fee Lee

According to a BBC report
<http://www.bbc.co.uk/worldservice/sci_tech/highlights/010924_asbestos.shtml>
only the north tower was insulated with asbestos and only to the 40th floor.
Since the planes hit above that level it is doubtful if either structure had
the degree of protection contemplated by the original design.

Once the upper floors detached from the vertical beams nothing could stop
total collapse. It is not clear that the asbestos coatings detached. The
report above says in part: "However, officials in New York recently said
dust samples tested at the site of the devastated World Trade Centre do
not show dangerous levels of the contaminant." If it came off, I would tend
to think it should have been present in large quantities in the dust that
swept through lower Manhattan.

Also, while there may be other coatings, I'm not aware of any with all the
unique properties of asbestos for this purpose.