Why...? - Season 1

First aired: 8/12/2019 9 episodes

Episodes

1. Why Bridges Collapse: The Genoa Disaster

Aired: 8/12/2019

On 14 August 2018, the Polcevera Bridge in Genoa collapsed, sending 27 vehicles plummeting to the valley below. 43 people lost their lives. It was Italy’s worst ever road-bridge disaster. This film tells the story of some of the people on the bridge that day and investigates what caused the bridge to fail so catastrophically.

2. Why Ships Crash

Aired: 1/18/2022

On 23 March 2021, the Ever Given – one of the largest container ships ever built – ploughed into the sandy bank of the Suez Canal, blocking the entire waterway. It stopped all traffic in one of the most important shipping lanes in the world for almost a week, causing a ‘ship jam’ of over 300 vessels and delaying deliveries of billions of pounds of vital food, fuel and medical supplies. The disruption to the global supply chain lasted for months. Using never-before seen footage, testimony from witnesses speaking for the very first time, and expert analysis, this documentary aims to uncover the inside story of the Ever Given accident. And with over 2,500 shipping incidents a year, the film also asks if this was just a freak accident or whether it reveals a serious weakness in the world’s critical supply chain.

3. Why Buildings Collapse

Aired: 7/5/2022

In 2021, Champlain Towers South – an apartment building near Miami – collapsed, killing 98 people. This film forensically examines what happened and asks: what went wrong? And could more buildings across the world be at risk of a similarly catastrophic fate? On 24 June 2021, Champlain Towers South – a 13-storey residential building in Surfside, Florida – collapsed in just 12 seconds. Fifty-five apartments were reduced to rubble, and 98 people lost their lives. What might have caused one of the worst building failures in modern history? There is still no official explanation. This programme examines what went wrong and investigates the implications for other buildings around the world, including those in the UK. Emotional eyewitness testimony, tense bodycam footage from first responders, news archive footage and 3D CGI animations are used to piece together the definitive, moment-by-moment account of this disaster.

4. Why Sharks Attack

Aired: 7/18/2023

8 June 2023. A shark attacks a 23-year-old Russian man swimming just metres from the beach in the Red Sea vacation resort of Hurghada, Egypt. Horrified tourists watch from the shore. His injuries are so severe that he dies before help can arrive. Within hours, videos of the attack spread on social media. It comes less than a year after two women were killed by sharks in the space of two days on the same stretch of coast. A spate of killings like this is unprecedented in the Red Sea. What brought these sharks into the shallow waters of luxury holiday resorts, away from their natural hunting grounds in the open ocean? Could mounting pressure from humans – fishing, tourism and man-made climate change – be altering how these apex predators live and hunt?

5. Why Planes Vanish: The Hunt for MH370

Aired: 3/6/2023

Ten years after Malaysia Airlines flight MH370 disappeared with 239 passengers and crew on board on 8 March 2014, this documentary looks at whether new radio technology may finally help locate the missing aircraft and asks what lessons can be learned to make aviation safer. 8 March 2014. A Boeing 777 carrying 239 passengers and crew from Kuala Lumpur to Beijing disappeared from air traffic controllers’ radar. It sent no emergency distress calls. The aircraft was never heard from again, but startling evidence soon emerged that Flight MH370 stayed in the air for a further seven hours. What could have caused the plane to divert so drastically off course? Was it struck by a catastrophic technical failure? Or was it hijacked – and if so, who by?

6. Why Trains Crash

Aired: 7/18/2023

On the evening of 2 June 2023, a devastating crash involving three trains killed nearly 300 people and injured more than 800 at Bahanaga Bazar station in India’s eastern Odisha state, as two passenger trains collided with a freight train. What caused one of the worst train disasters in modern history? This film forensically examines what went wrong and asks whether it could have been prevented and if enough is being done globally to ensure our railways are safe. The documentary explores what could have caused this disaster and, using case studies of other train accidents, unpacks the science and engineering behind them. It also investigates the pressure put on railway services by maintenance budgets, the greater need for upgrading ageing infrastructures and the significant impact of climate change.

7. Why Bridges Collapse: The Baltimore Disaster

Aired: 12/5/2024

MV Dali, a huge container ship, crashes into the Francis Scott Key Bridge in Baltimore, tragically killing six people and completely destroying the bridge. Investigators reveal how it happened.

8. Why Cities Flood: Spain's Deadly Disaster

Aired: 6/24/2025

On 29 October 2024, a powerful storm hit the area around Valencia in Spain. Torrential rain fell on the hills to the west of the city, causing devastating flash floods. Across the province, 228 people died. It was Europe's deadliest single storm flood since 1967.

9. Why Planes Crash

Aired: 10/13/2025

In December 2024, a passenger jet crashes at Muan International Airport in South Korea, killing 179—the worst aviation disaster in the country’s history. Weeks later, a military helicopter collides with a passenger plane over Washington DC, killing 67. In February 2025, a commuter jet crashes in Toronto; all survive. Then in June, an Air India flight crashes just after take-off, killing 260 with only one survivor. With global air travel expected to reach 4.9 billion passengers this year, can lessons be learned from this alarming series of disasters? Featuring eyewitness accounts, expert analysis, and shocking footage, this documentary investigates what went wrong.