.Background: the glowing fountain
This event was essentially unique: no other similar conspicuous flows were observed anywhere else in the Twin Towers or in other buildings affected by the 9/11 attacks.
NIST did report (NCSTAR1-5A, Chapter 9, Section 9.3, page 331) a six-second "shiny silver string" of "liquid pouring intermittently" from a window on the 78th floor of WTC2.
The material "looked as if it was glowing", but as shown by the picture on the right (Figure 9-32 of the NIST report), this was an extremely modest phenomenon, exhibiting none of the conspicuous yellow-red glow and splashing, fountain-like behavior of the event on the 80th floor. Some alternative theories regarding the 9/11 attacks consider this more conspicuous fountain as evidence of intentional demolition of the Twin Towers, performed by using thermite or similar compounds to melt and cut through the columns.
The glowing fountain, according to these theories, would be an effect of this melting process. However, such theories fail to explain why no other fountains were seen anywhere else. These theories also overlook a very important fact: the glowing fountain was located where the debris of Flight UA175 exited from the building (an engine, a landing gear and a fuselage section were found). This might not be coincidental. The large fountain on the 80th floor of WTC2 is discussed in the FEMA report and in NIST's NCSTAR1-5A report, Chapter 9, on pages 374-387. NIST notes that the flow began intermittently at 9:53:51. At 9:57:32 the flow "increased dramatically" and remained "nearly continuous until the tower collapsed".
UPS vs UPS?
However, some rather unusual clues found by Enrico Manieri suggested in 2006 an alternative explanation.
Because if there was an uninterruptible power supply on the 80th or 81st floor, in the northeast corner, the impact of the aircraft and the collapse of the floors above, with their conducting metal parts, would have caused countless short-circuits of the batteries, providing currents of tens of thousands of amps (as calculated in this article), which can produce unimaginable thermal effects.
In addition to this, abundant hydrogen, which is highly flammable, is generated during the shorting of a UPS system (it is also generated during normal operation, hence the need for special ventilation, firefighting equipment, and restricted access), and it is well-known that batteries are prone to explode in case of fire (hence the warning printed even on small AA batteries).
This inferno would have easily melted the lead of the batteries, whose melting point is even lower than aluminum's and is well within the temperature range of a building fire and far lower than the melting point of steel.
This would have allowed the molten metal to flow without damaging the steel columns, which is what the visual evidence shows.
In other words, the catastrophic shorting and meltdown of a UPS system would provide a very plausible and simple explanation for the glowing fountain.
modifications were made in 1991 to reinforce the 81st floor of WTC 2 in an area occupied by the United Parcel Service.
Modifications were made in 1999 to floor 81 in an area of the floor occupied by Fuji Bank to accommodate the weight of an uninterruptible power supply.
Both of these modifications are documented in the section of the NIST WTC Investigation Report known as NCSTAR 1-1C (go to http://wtc.nist.gov/NISTNCSTAR1-1C.pdf).
What is perhaps confusing is that both modifications were made to areas where there are two-way trusses (the corners of the building) and the acronyms (UPS for "United Parcel Service" and "uninterruptible power supply") are the same.
However, these modifications were made eight years apart for two different tenants, so there is no link between them.
I hope this answers your question.
Michael Newman Spokesman, NIST WTC Investigation "
NIST, therefore, confirms that an Uninterruptible Power Supply system was located on the 81st floor of the South Tower, where the glowing fountain was observed.
In other words, there is a clear explanation for this phenomenon which does not require the involvement of thermite or other unlikely conspiratorial technologies. As regards NIST's statement that United Parcel Service was indeed a tenant of the 81st floor, we are awaiting a clarification from the company.
.Other articles in English language: