The grandstand of De Goffert, the stadium of football club NEC, collapsed in mid-October due to an excessive load and an error in the calculation of the design.

That mistake was made in the design of the grandstand 22 years ago.

Engineering firm Royal HaskoningDHV announced this on Friday morning.

The stands, where the branch is located, collapsed on Sunday 17 October shortly after the match between NEC and Vitesse.

According to Erik Middelkoop, of the Royal HaskoningDHV, the part of the stand could carry the group of people standing there, as long as they "behave reasonably calmly".

That was not the case after the derby against Vitesse.

Because Vitesse had won, the supporters from Arnhem were frantic and had gathered en masse at the edge of the stands and jumped up and down there.

The concrete was not designed for this and therefore broke due to the excessive load.

The broken concrete was collected by a container that stood under the grandstand, so there were no casualties.

NEC played one home game after the incident, which was played without an audience against FC Groningen.

This message is being completed.