A FIVE-LEVEL building under construction in Bratislava collapsed without warning on Sunday morning, July 1, but there were no injuries or deaths. The building was to house a wellness centre and parking for 3nity, a multifunctional development on Plynárenská Street that is still under construction, though one residential building is complete and occupied. The collapse of the structure left a crater filled with glass and other construction debris. No reason for the collapse of the building is yet known but Slovakia’s Police Corps has started a criminal investigation to investigate the collapse.

“A criminal investigation has been initiated based on the offence of public endangerment,” stated Tatiana Kurucová, the Bratislava regional Police Corps spokesperson, as quoted by the TASR newswire. “An expert in construction has been deployed to find out why the building collapsed.”

When the 3nity development is completed it will consist of 411 flats in its residential part in three high-rise buildings and a commercial area with shops, services and offices. The developer is Nadlan, a member of the Vara Group from Israel, which has been active in Slovakia since 2005, according to the 3nity website. ASB magazine wrote that the total project costs are projected at €80 million.

The area around Plynárenská Street has several administrative buildings and headquarters for several large companies, including that of SPP, Slovakia’s primary natural gas utility. Before the 2008 financial and economic crisis, there had been plans of making the area into the ‘Manhattan of Bratislava’ but subsequent construction projects were delayed or abandoned under the impacts of the crisis.

The 3nity project is still under construction even though flats in one of the high-rise tower are completed and some are occupied. After the collapse of the future wellness centre and parking garage building, which had two above-ground floors and three underground floors, residents of the occupied tower were evacuated due to concerns about possible structural damage. But the residents later returned to their homes after specialists conducted an on-site inspection and pronounced the building safe.

Parts of the development are under active construction and if the building had collapsed during a work day there may have been injuries or deaths as dozens of people are working at the construction site.

“The skeleton of the wellness centre was completed and finishing works were to start,” stated Iveta Adamcová of Nadlan, as quoted by the Trend economic weekly, adding that the wellness centre had an open date in 2013.

The developer stated that the collapse of the skeleton of the building did not affect the statics of the other buildings in the area and said it plans to erect the building again and open the wellness centre and parking garage in 2014.

The developer was silent about possible reasons for the collapse.

“During this phase we cannot estimate damages,” said Adamcová, adding that this will part of its further investigation as well its attempt to determine the reasons for the collapse.

Metrostav, a Czech construction company, was building the structure that collapsed and the TASR newswire reported that the firm is rechecking its statics calculations.

Experts interviewed by the Trend weekly indicated that there could be three reasons behind the collapse: incorrect calculation of the roof’s load and the underlying statics of the building; faulty construction processes; or insufficient drainage on the roof as it was designed as a ‘green roof’ to be covered with vegetation.

A structural engineer told Slovakia’s public-service TV broadcaster, RTVS, this collapse should not have occurred if norms and safety directives were followed.

“For such a collapse, the mistake must have been enormous,” Ján Kyseľ, head of the Association of Statics Experts told RTVS. “We saw the whole course [of the collapse] and those images which are available indicate that there had to be some kind of overloading.”

Kyseľ told the Sme daily that a set of imperfections might have led to the collapse, stating that developers and builders sometimes focus on reducing costs rather than on quality construction.

The Association of Statics Experts also called for more supervision of construction sites and said that there had been more oversight in the past in Slovakia than there is now.