All construction projects involve some degree of risk. Most project managers will take Health and Safety steps in an attempt to mitigate these risk, but it is often impossible to remove risk altogether. In other cases, corners are cut during the construction project, which can put a lot of people in danger. The following three cases are examples of some of the worst construction accidents of the past decade from around the globe.

Mecca Crane Collapse

In 2015, 111 members of the public were killed at the Grand Mosque in Mecca when a crawler crane fell onto the Masjid al-Haram during a storm. Nearly 400 other worshippers were injured in the accident. Those killed included; Bangladeshi, Egyptian, Pakistani, Indonesian, Iranian, Indian, Turkish, Malaysian, Nigerian, British, Algerian and Afghani citizens. At the time of the collapse, the Grand Mosque area was busier than usual as the city was preparing for the Hajj pilgrimage.

The Masjid al-Haram is visited by hundreds of thousands of people during each Hajj period. At the time of the collapse, the Saudi authorities were attempting a construction project to expand the Grand Mosque area to reduce stampede risks. The large crane was part of the construction project. During a powerful sandstorm, the boom of the crane fell onto the east side of the mosque. Many pilgrims were trapped inside the building as exits were sealed by the accident. The Saudi Red Crescent Authority were forced to launch a large-scale search and rescue mission to find people who were trapped under the debris.

The official Saudi enquiry into the incident placed partial blame onto the construction company. The report stated that the crane was in the wrong position for such high winds. German investigators found that there were no structural flaws with the crane itself; however the boom should have been secured by its operators when the wind started to pick up speed. The German team also declared that the use of the crane in winds of up to 105 km/h vastly exceeded manufacturer tolerances.

Lotus Riverside Complex

In 2009, Block 7 of the Lotus Riverside Complex in Shanghai completely collapsed. The building, which was 1 block out of 11, was almost finished at the time of its collapse. The development company which were financing the Lotus Riverside Complex had already sold nearly 500 of the expected 629 flats which were due to constructed in the blocks of 13-storey buildings. Many of those who had already bought properties within the other blocks fought for refunds amid safety concerns about the whole development.

The Lotus Riverside Complex collapse was unique because the building itself appeared to be almost completely intact after the fall. Block 7 narrowly missed other blocks in the development as it fell, which could have caused a deadly domino effect. Due to the fact that the collapse happened at 5am on a Saturday, only 1 worker was killed in the incident but 1 is still too many.

Upon inspection, the stabilising structures at the base of the tower appeared to be far too short for the proposed height of the building. These types of precast concrete pilling were outlawed in Hong Kong but were permitted in mainland China. Official investigations found that the collapse was due to incorrect earth movement around the building site. Large quantities of earth had been moved from the development area onto the banks of a nearby creek. The weight of the excess earth caused the bank to collapse and then water completely saturated the development land. The sodden earth eventually started to sink, which caused the building to topple.

Didcot Power Station Collapse

In 2016, a section of the Didcot A power station collapsed whilst it was being prepared for demolition. One person was killed outright in the blast and three men were declared as missing but presumed dead. Due to the nature of the incident, it actually took months to recover the bodies of these men. In addition to the deaths, 50 people were treated for dust inhalation which was caused by the collapse occurring at an unexpected time.

Although many people initially feared that the collapse was as the result of a terrorist act, it later became clear that the pre-demolition process had weakened the building too much. The company that was in charge of the demolition had classified the work as the highest category of risk, and had had the structure voluntarily checked by a third party before proceeding further with the weakening work. Both parties believed that everything had been done to mitigate the risks associated with this type of structure.

At present, the construction industry is still awaiting the results of an inquest into what caused the Didcot A boiler room to collapse before the controlled explosion was carried out. It took over 6 months before the final body could be removed from the building.