The stadium had been very close to completion when the boom of the Liebherr LR 11350 crawler crane fell while positioning the last module of the roof covering. It landed over a circulation area at the east end of the stadium and a large LED display. Two workers were killed.
All investigations conducted to date by the Liebherr crane experts, including those at the accident site, have shown that the Type LR 11350 crane had no technical defects. Instead the cause was that the ground was not sufficiently stable for crane travel with a suspended load on the day of the accident.
The ground under the crane evidently gave way, according to Liebher, causing the crane to sink. In doing it so reached an inclined position at which it was not allowed to operate. The excessively inclined position caused massive overloading of the crane, which led to the fracture of some of its components and following this to collapse of the complete load-bearing structure. An independent, internationally acknowledged crane expert has come to the same conclusions, according to Liebherr.
Analysis of the data logger by Liebherr showed that it had not been recording data since November 2012. This fact can be checked by the parties involved, since the information was jointly copied and handed over immediately after the data logger had been recovered. “However, a data logger can never influence crane functions and certainly not cause any accidents since it is simply a device that records data,” said Liebherr.
The cause of the accident as determined by Liebherr's analysis can be confirmed by subsequent static-load calculations, the company said. Liebherr said that it assumes that all the reports currently being prepared about the accident will not reach any different conclusions.
“Liebherr is extremely saddened by this tragic accident and the two fatalities, and expresses its deep sympathy to their families,” the company’s statement concluded. “As the crane manufacturer Liebherr continues to do everything in its power to help bring the accident investigation to a speedy and logical conclusion and expects the parties directly involved in the accident to do the same. Liebherr will also continue to cooperate closely with the Brazilian authorities.”