Listening to television news journalists describing the devastating collapse of the Champlain Towers in Surfside, Florida, as being the only time in the United States that such a collapse has occurred, I knew that I was aware of others, particularly the collapse of the Harbour Cay Condominium Tower in Cocoa Beach, Florida in 1981. Also I recall the collapse of the Hard Rock Hotel in New Orleans in 2019. Even though both of these midrise towers were under construction and had not yet been occupied by residents, they were complete building structures when they failed and there was still loss of life. Eleven workers died in the Harbour Cay incident, and three workers died in the Hard Rock Hotel collapse.
The potential loss of life in Surfside however will tragically surpass these numbers of course, making it the greatest loss of life collapse in U.S. history. That part is true, unfortunately.
As noted above, there have been other residential midrise residential buildings that have collapsed in the U.S. Up to six over the last 100 years. All were reinforced concrete buildings. A majority of the collapses happened during construction, but only after the building frame had been erected.
1. HARBOUR CAY CONDOMINIUM
COCOA BEACH, FLORIDA—Collapsed March 27, 1981: A 5-story cast in place concrete-framed condominium structure which collapsed after the completion of the roof slab, killing 11 workers and injuring 23.
In terms of causes of the Harbour Cay collapse, without getting into the minute details of subsequent investigations, the structural design of the 5 story condominium structure was simply flat out wrong. There were multiple mistakes in the original working drawings. The 8” slab thickness was too shallow when taken into consideration the 4.5” height of the plastic chairs that support the reinforcing steel. This left too little concrete coverage atop the steel according to one report that I read. A report by the National Bureau of Standards noted that there was insufficient shear punching capacity in the 5thfloor slab at column connections.
How does this happen? In this case the two engineers involved were both retired NASA engineers and not qualified in the design of concrete structures. They both lost their licenses.
2. HARD ROCK HOTEL
NEW ORLEANS, LA—Collapsed October 12, 2019: According to OSHA “floor beams on the 16th floor were under designed in load capacity and structural steel connections were inadequately designed, reviewed, or approved”, the result of which the collapse occurred with the deaths of three workers and injuries to 30:
3. 2000 COMMONWEALTH AVENUE
BOSTON, MA—Collapsed January 25, 1971: A 17 story cast in place concrete condominium tower. The collapse killed 4 workers. It happened so slowly most were able to escape. Although there were many factors, the trigger appeared to be the cold weather retarding the strength gain of the newly placed concrete. Other factors are listed below, in addition to not following the concrete design strength specifications during construction:
4. L’AMBIANCE PLAZA
BRIDGEPORT, CONN.—Collapsed April 23, 1987: Another 16-story concrete residential tower that collapsed, except the construction method here was one of “lift slab” construction where the connections to the columns apparently failed after the entire building was constructed. 28 workers were killed and 22 injured.
The failure, it was determined, was the result again of poor design and execution. Various factors included improper alignment of the columns and the improper curing of the concrete as well as failure of structural connectors. Like the other cases it was not one design or construction error, but several different deficiencies that get triggered by one “trigger event” that causes the whole house of cards to fall. Images below:
5. SKYLINE PLAZA
FAIRFAX COUNTY, VIRGINIA—Collapsed March 2, 1973: 14 workers died and 30 others injured in the collapse of this 24-story cast in place reinforced concrete midrise condominium in northern Virginia. Apparently after the building was completely topped out, formwork and shoring were removed prematurely causing the collapse from the top down:
6. GRAND CENTRAL HOTEL
NEW YORK—Collapsed August 3, 1973 (built 1870): This 400 room 8 story hotel opened in 1870 and was one of the largest hotels in the country. However, although it took 103 years to fail, it did so in the end. Yet very slowly. There was time though for most of the 300 residents to evacuate, but even so, four residents lost their lives. Neglect and illegal interior renovations had over time weakened the structure to the point that residents reported cracks and bowing structural walls until in 1973 the entire building just simply collapsed as seen below:
Which brings the thinking back to the premature conclusions TV journalists, some of whom I respect, have jumped to in regard to how to go about figuring out what happened in Surfside. As seen above, there have been other collapses and loss of life over the years, and it has taken time in each case to determine the causes. So for journalists to suggest, as I have seen and heard, that the tragedy in Surfside is the only time this type of catastrophic failure has occurred in the United States is not correct.
There are 3 basic steps to investigate I would think, the first being the design (as noted above in the Harbour Cay example), the second being the construction means and methods, and third being the examination after the collapse for clues as to corrosion and evidence of “punch shear” damage where the column “punches through the attached concrete floor slab” when the connection to that column fails. The investigation centers on to what the trigger was that initiated the event. Having said this however, Joe DiPompeo, president of the American Society of Civil Engineers has said that “There’s got to be a very specific sequence of events that somehow evaded all the fail-safes in the code and in the design and construction of the building.”
There are professionals currently looking at these issues through examination of the original 1979 construction documents and calculations as well as any records of the 1981 construction procedures and subsequent maintenance over the years. We will have to wait on the data to see and not depend on superficial speculation of TV journalists.
Blog Post written by David Tritt, Senior Architect.
