He was taken to hospital in a serious condition. However, his injuries are no longer considered life-threatening. The accident happened at around 10am on Friday morning.
The trailer of the lorry hit a number of cars before crashing into the bank. The lorry driver has been questioned and examined by a police surgeon.
Sarah Callewaert of the Leuven Judicial Authorities told VRT News "He doesn’t remember anything about the accident”.
"He says that he became unwell”.
According to the police surgeon that examined him there are indications that this could be the case.
"This also tallies with findings of the road traffic expert who found no evidence that he had tried to break”.
The accident investigation is continuing. However, the Judicial Authorities say that the driver having become ill behind the wheel is the most likely cause.
"The CCTV images are now being examined and we are waiting for the results of a blood test carried out on the driver. We currently have no indication that the man was under the influence of any substance”, Ms Callewaert added.