Risk management case study : Highland tower

The other day i was teaching "Project Risk Management" to a few young grad. Given the condition to teach young minds about what is Risk Management and i knew that i got to make it sticky as they always say "ounce of emotion worth tonnes of fact".

At that point it strucks my mind, "what will you do if a landslide an estimated 100,000 square metres of mud - a mass equivalent to 200 Boeing 747 jets came rushing to your house".

And from there i got their attention and my made presentation like miniskirt, short enough to cover the subject and long enought to hold the young engineers attention"

I used Highland Towers as my case study supported findings from History Channel documentary. And if there is any facts distorted, you will know who to find :)

Just to share few interesting points.

Part 1
http://www.youtube.com/watch?v=9sNbFUoPJqg
Part 2
http://www.youtube.com/watch?v=0vO_t_cT0l4
Part 3
http://www.youtube.com/watch?v=ypedar3Dnww
Part 4
http://www.youtube.com/watch?v=EoRICWEy-B4

 

“ The landslide contained an estimated 100,000 square metres of mud - a mass equivalent to 200 Boeing 747 jets’’...Impact on Highland Towers"

Engineers explaining on the observation.

Before we get into further details, i believe that from the documentary the reason that lead to disaster was mainly due to the stability of slope was greatly decreased by "uncontrolled water flow and rudimentary retaining walls unable to bear the sudden increase in load — mud, boulders, debris — that were loosen by water".

And why was it ?

It was found that the specific causes of the collapse were damage done by water that was diverted by another development project up the hill and which flowed behind the Highland Tower blocks. The existing drainage system or the pipeline could't contain the water no more and overflow to the soil.

The Highland Towers collapse was an apartment building collapse that occurred on 11 December 1993 in Taman Hillview, Ulu Klang, Selangor, Malaysia.

The collapse of Block One of the apartments caused the deaths of 48 people and led to the complete evacuation of the other two blocks due Cause of structural failure

Behind the Towers was a small stream of water known as 'East Creek'. East Creek flowed into the site of the Towers before the Towers' construction. Later, a pipe system was built to divert the stream to bypass the Towers.

In 1991, a new housing development project, known as 'Bukit Antarabangsa Development Project', commenced on the hilltop located behind the Towers. As a result, the hill was cleared of trees and other land-covering plants, exposing the soil to land erosion that will cause land slide .

The water from the construction site was diverted into the same pipe system used to divert the flow of East Creek. Eventually, the pipe system became overly pressurized with the water, sand and silt from both East Creek and the construction site. The pipes burst at various locations on the hill, and the soil had to absorb the excessive water. The monsoon rainfall in December 1993 further worsened the situation.

The water content in the soil had exceeded a dangerous level, and the soil had literally turned into mud. By October 1992, the hill slope had been almost flooded with water, and it was reported that water was seen flowing down the hill slopes and the retaining walls.

Soon after, a landslip took place and destroyed the poorly-constructed retaining walls. The landslide contained an estimated 100,000 square metres of mud - a mass equivalent to 200 Boeing 747 jets. The soil rammed onto the foundation of Block One, pushing it forward for a while before causing it to snap and bringing down the apartment block.

A month before the building fell, in November 1993, residents began to see cracks forming and widening on the road around the Highland Towers, a sign of collapse but unfortunately, no further investigation was carried out.

Soon after, a landslip took place and destroyed the poorly-constructed retaining walls. The landslide contained an estimated 100,000 square metres of mud - a mass equivalent to 200 Boeing 747 jets. The soil rammed onto the foundation of Block One, pushing it forward for a while before causing it to snap and bringing down the apartment block.

A month before the building fell, in November 1993, residents began to see cracks forming and widening on the road around the Highland Towers, a sign of collapse but unfortunately, no further investigation was carried out.

“ The landslide contained an estimated 100,000 square metres of mud - a mass equivalent to 200 Boeing 747 jets’’

A month before the building fell, in November 1993, residents began to see cracks forming and widening on the road around the Highland Towers, a sign of collapse but unfortunately, no further investigation was carried out.

Seconds from Disaster

·October 1992

·Water began to flow down the hill slopes due to the flooding caused by the burst pipes.

·November 1993

·Cracks began to form and widen on the road leading to the towers

·December 11, 1993: Block 1 of the Highland Towers collapses at 1.35 pm.

·124 members of the Federal Reserve Unit (FRU) and about 30 military personnel and engineers from Batu Cantonment Camp and Wardieburn Camp are deployed for search and rescue. Hundreds of policemen, firemen and Kuala Lumpur City Hall (DBKL) rescue teams, Malaysian Red Cresent Council volunteers arrived earlier.

·Rescue team spots somebody waving a stick. A maid of one of the residents at Level 7, Umi Rashidah Khoruman, 22, and her daughter Nur Hamidah Najib, 18 months are found.

·Shizue Nakajima, 50, a Japanese women was also pulled from the debris but pronounced dead at 12 midnight in Kuala Lumpur Hospital (HKL). Dr Abdul Wahid from HKL Shahrum stated Nakajima suffered severe internal bleeding.

·Prime Minister of Malaysia, Datuk Seri Dr. Mahathir Mohamad, Deputy Prime Minister Datuk Seri Anwar Ibrahim and many cabinet ministers visit the site.

·December 12: Residents of Block B and C of Highland Towers are ordered to vacate their homes after declaring unsafe. Search and rescue teams from Singapore, France and Japan arrived in Malaysia to help. Nuri and Alouette helicopters from the RMAF were also despatched.

·December 13: A team from France with two rescue dogs joins the operation. They use heartbeat detectors to search for survivors and digs a 4.5 meter hole for access. A Committee Cabinet is established specifically to deal with problems relating to the Highland Towers tragedy.

·December 15: Rescuers find six bodies. Four are believed to be of two Koreans and two locals. Rescue teams decides to use machines to break concrete and steel as well as bulldozers to remove debris to open a route.

·December 16: Umi and Rashidah Nur Hamidah are released from HKL.

·December 17: The Cabinet Committee agrees to abandon rescue efforts.

·December 18: Rescue teams find six more bodies including one child.

·December 19: Rescue teams find three bodies. One of a woman, located about eight meters inside the parking area, was found at 7 p.m. The second body, also a woman, was found near the first body at 8.30 p.m. while the third, a man, was found at 10.15 p.m. the night.

·December 20: So far, 25 corpses, including one who embraced the Qur'an found in Level 12 are discovered. Also found were the remains of a woman wearing a sari and shielding a child.

·December 21: The police confirms that 48 bodies were recovered from the Highland Towers debris.

·December 22: The search is ended. Dr Nik Hassan Nik Ramlan is appointed chairman of the Technical Committee of Investigating the Highland Towers tragedy.

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Takeaway from the lesson :

 You have to do comprehensive risk management process even to the extend of doing residual risk management.