Explosion in the pilot neighborhood

This morning we were shocked just after 08:00 am by a violent bang. The office was shaking and then it was quiet. What happened?
Moments later, the phone calls and there appears to be a blast in the pilot neighborhood (Bekkerveld-Heerlen).
A building that was being renovated, was hit by the explosion. The top of the 4 floors wiped out completely. Three injured and a lot of damage to windows, frames and tiles of surrounding houses.
And of course lots of disaster tourists.