History Series / SecondsFromDisaster

** Also could have prevented the eponymous disaster in "Collision on the Runway". When van Zanten saw the Pan Am plane on the runway in front of him, he panicked and tried to take off even though he had insufficient speed to lift off, lifting the nose and consequently dragging the plane's tail down the runway, which slowed the plane's acceleration and actually delayed them getting up to takeoff speed. Given that even with that delay, they got off the ground at the last second (but too late to prevent a collision), had van Zanten continued to carry out the takeoff roll as if there wasn't another plane right in front of him, as crazy as that would seem to be in the moment, he almost certainly could have lifted off just in time to clear the Pan Am, making the incident a near-miss instead of a tragedy.

** "Paris Train Crash/Runaway Train": A woman gets a train, not realising that its schedule has been changed. When she realises the train will not stop at her station, she pulls the emergency brake, and gets out. While trying to reset the emergency brake, the train driver accidentally pulls shut a valve supplying air to his train's brakes. Instead of waiting for an engineer to be called out as SNCF policy dictates, the driver incorrectly diagnosed an airlock, and bleeds out the air to the brakes, leaving the train with no braking power. This leaves him unable to stop his train, and in his panic he forgets about the electric brake, and is left speeding towards the Gare de Lyon with no ability to stop the train.

The driver was instructed to skip the next train station, which was on level ground, and - evem with defective brakes - would have enabled the driver to bring the train to a standstill. However, by skipping this stop, he picks up speed, and the tracks in towards Gare de Lyon are on a downward gradient, causing him to pick up further speed.
The station's controllers realise a train is out of control, and implement a general shutdown, bringing each train to a halt. However, this general shutdown also automatically resets all points configuations, meaning that the runaway train, instead of going into an empty platform, goes into a platform with another train already there waiting (which itself should have long since left Gare de Lyon, and was only waiting since the guard for the train had not yet turned up).

** "Paris Train Crash/Runaway Train": A woman gets a train, not realising that its schedule has been changed. When she realises the train will not stop at her station, she pulls the emergency brake, and gets out. While trying to reset the emergency brake, the train driver accidentally pulls shut a valve supplying air to his train's brakes. Instead of waiting for an engineer to be called out as SNCF policy dictates, the driver incorrectly diagnosed an airlock, and bleeds out the air to the brakes, leaving the train with no braking power. This leaves him unable to stop his train, and in his panic he forgets about the electric brake, and is left speeding towards the Gare de Lyon with no ability to stop the train. The station's controllers realise a train is out of control, and implement a general shutdown, bringing each train to a halt. However, this general shutdown also automatically resets all points configuations, meaning that the runaway train, instead of going into an empty platform, goes into a platform with another train already there waiting, causing the Gare de Lyon train crash.

** "Paris Train Crash/Runaway Train": While trying to reset the emergency brake cord, the train driver accidentally pulls shut a valve supplying air to his train's brakes. This leaves him unable to stop his train at the end of the line, resulting in the Gare de Lyon rail accident.
*** Not to mention that the entire sequence of events would never have happened if the emergency brake hadn't been pulled in the first place.

** "Comet Air Crash/Crash of the Comet": The decision to secure a window with rivets instead of glue (as originally designed) left a microscopic manufacturing defect in the fuselage of ''BOAC Flight 781''. Over time, the defect grew into a fatigue crack. The fatigue crack then failed, leading to ExplosiveDecompression, causing [[TitleDrop the crash of the Comet]]. The crash crippled the promised rise of British Aviation company ''de Havilland'', allowing two companies, '''Boeing''' (which until then was mostly known for their military aircraft) and '''Douglas''' (which later merged with [=McDonnell=] Aircraft to become [=McDonnell=] Douglas) to leave them in the dust forever. Also, the subsequent inquiry into the crash resulted in unprecedented investigative techniques (such as ''wreckage reassembly'') being developed; techniques that form the cornerstone of accident investigations to this day.

* CryingWolf: In "Paris Train Crash", it's noted that the brake system was known to overload and jam when the emergency brake was pulled, so when the driver found that the brakes wouldn't release after he reset the emergency brake, he (rather understandably) believed that it was the same malfunction, rather than realizing that he had actually tripped a failsafe designed to stop the train from moving with insufficient brake power. Adding to the problem was that there were no additional indicators to tell the driver that a safety system had been activated in response to insufficient brake pressure, meaning there was no clear way to distinguish between an overload and tripping the failsafe.

* CryingWolf: In "Paris Train Crash", it's noted that the brake system was known to overload and jam when the emergency brake was pulled, so when the driver found that the brakes wouldn't release after he reset the emergency brake, he (rather understandably) believed that it was the same malfunction, rather than realizing that he had actually tripped a failsafe designed to stop the train from moving with insufficient brake power. Adding to the problem was that there were no additional indicators to tell the driver that he had a brake pressure problem.

* ForWantOfANail: Often a major final or initiating factor in the disaster.
** "Comet Air Crash/Crash of the Comet": The decision to secure a window with rivets instead of glue (as originally designed) left a microscopic manufacturing defect in the fuselage of ''BOAC Flight 781''. Over time, the defect grew into a fatigue crack. The fatigue crack then failed, leading to ExplosiveDecompression, causing [[TitleDrop the crash of the Comet]]. The crash crippled the promised rise of British Aviation company ''de Havilland'', allowing two companies, '''Boeing''' (which until then was mostly known for their military aircraft) and '''Douglas''' (which later merged with [=McDonnell=] Aircraft to become [=McDonnell=] Douglas) to leave them in the dust forever. Also, the subsequent inquiry into the crash resulted in unprecedented investigative techniques (such as ''wreckage reassembly'') being developed; techniques that form the cornerstone of accident investigations to this day.
** "Paris Train Crash/Runaway Train": While trying to reset the emergency brake cord, the train driver accidentally pulls shut a valve supplying air to his train's brakes. This leaves him unable to stop his train at the end of the line, resulting in the Gare de Lyon rail accident.
*** Not to mention that the entire sequence of events would never have happened if the emergency brake hadn't been pulled in the first place.
** "Inferno in Guadalajara": One very small water pipe bent over a gas main, as well as creating a U-bend in the main sewer line in order to get a subway tunnel through, eventually causes a massive sequential explosion which kills over 200, cripples many more, and causes hundreds of millions of dollars in property damage.
** Essentially the same thing happened four years later in San Juan, Puerto Rico, this time with a propane pipe cracking under the weight of settling concrete and groundfill above due to a sharp bend; [[CallBack the Guadalajara explosion is even referenced]] and footage from that episode shown.
** The faulty experimental engine which downed British Midlands Flight 092 and caused a couple other planes to make emergency landings was never tested in flight prior to release, instead being only wind-tunnel tested; a flight test would almost surely have uncovered the weak fan blade design.
** "Crash of the Concorde": A strip of metal that had fallen off another plane and was lying on the runway burst one of the Concorde's tires, which sent debris into the undercarriage that severed a wire and knocked fuel loose from one of the tanks, setting the plane's wing on fire.
** "Collision on the Runway" is loaded with these. Even by the standards of a show that deals in DisasterDominoes, an absurd number of factors had to come together for the accident to happen; the lack of any one of them would have averted the accident.
*** The most blatant single example is that when the KLM pilot said he was ready to take off, the tower told him to "stand by for takeoff", while the Pan Am tried to warn him that they were still on the runway. Either message alone would have conveyed to the captain that he needed to wait, but because both were sent at the same instant, the KLM radio could not process them and drowned out both messages in a burst of static.
** "Columbia's Last Flight": A piece of foam from the external tank broke off during takeoff and hit the leading-edge tip of ''Columbia's'' left wing. This had been a longtime problem with the shuttle program, dating all the way back to the first mission, and nothing too serious came of it before. This time, however, the foam just happened to hit a critical spot on the ship's wing, allowing hot gases to seep in during the shuttle's reentry, tearing it apart.
** “Plane Crash in Queens/New York Air Crash”: The first officer had been incorrectly trained to use alternating aggressive rudder inputs to recover from wake turbulence, which he did in response to the turbulence caused by the JAL flight in front. Had he not done this, American Airlines Flight 587 would have leveled out on its own. Instead, his aggressive use of the rudder caused the vertical stabilizer to break off, leading to the plane losing complete control.
** "Crash Landing In Sioux City": Part of the metal in the rear turbine was improperly forged, which resulted in a hairline fracture that slowly grew larger and larger over seventeen years. During the fateful flight, the crack had grown too big and finally split the turbine in half.

->''"Disasters don't just happen. [[DisasterDominoes They're a chain of critical events]]. Unravel the fateful decisions in those final, [[TitleDrop Seconds from Disaster]]."''