The Empire State Building survived a plane crash in 1945 when a B-25 bomber crashed into the building. Several factors contributed to its survival: the building was constructed with fireproofing materials like reinforced concrete, steel protected by paint, and cinder concrete encasement; it had a standpipe water delivery system that extinguished the fire quickly; and its compartmentalized design contained the fire. Despite its relatively low weight, the aircraft's impact could have been catastrophic if it was carrying bombs, as the greatest threat in such crashes is from ensuing fires. Lessons included the importance of fire protection and not using elevators during fires.

1. B-25 Empire State Building
Crash
Presentation by Maya Bhattacharya

2. The Surprise
Other plane crashes have
caused uncontrollable fires and
collapses
●
The Empire State Building fire
was extinguished in 40 minutes
and there were very few
casualties
●
How did the structure survive
the impact of a B-25 Mitchell
bomber?
●

3. The Crash Facts
Date: July 28, 1945
Time: 9:41 AM
Location: 78th &
79th floors
Why: The pilot was
disorientated in the
fog and flew less
than the
recommended 2,000
feet

4. Reinforced Concrete Structure
All structural steel was protected by
iron oxide and linseed oil paint
(prevents corrosion)
●Steel was then covered in an asphalt
coat (protected the steel when it came
in contact with concrete)
●The steel columns were enclosed in
cinder concrete (additional fireproofing)
●

5. Other Structural Facts
Heavy internal bracing
●Thick masonry (limestone and
granite)
●Good redundancy (duplication of
critical components)
●

6. Water Delivery System
Water tanks were inside the building
instead of on the roof
●70 miles of piping to deliver water
through building
●This standpipe system extinguished
the fire quickly
●

7. More Fireproofing
1930 Requirement: All high rise
buildings must have fireproof stairwells
●The Empire State Building was:
●
●
●
●
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Compartmentalized
Each floor was self-contained
Each floor and each room separated
by 5 partitions
Each floor had their own elevator and
utility shafts enclosed by thick
masonry walls

8. The Big Picture
The building didn’t collapse because
of the relatively low aircraft weight in
relation to the building
●However, in such crashes, it’s the fire
that creates a collapse
●If the B-25 had been carrying bombs,
the event would have been
catastrophic
●

9. Lessons Learned
Planes should remember not fly lower than 2,000
feet
●Fire protection precautions are very important
●Never use an elevator in a fire – only one
emergency braking system success is known – look
up Betty Lou Oliver
●The W.T.C. structural engineers accounted for
blast resistance, which is why the towers remained
standing for 45 to 90 minutes afterward. However,
their design did not account for a fuel fire.
●

10. Big News
1000 feet above the
sidewalk

11. Other Plane Crashes
40 Wall Street (1946)
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NYC skyscraper
W.T.C. (2001)
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NYC Twin Towers
Pirelli Tower (2002)
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Milan, Italy
Belaire Apartments (2006)
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NYC