As providers in the business of critical infrastructure they need to comply to the HIGHEST physical and digital security requirements, which includes taking preventive measures against acts of terrorism.
Not much is known about this case yet though, it's possible that their preventive procedures failed but their resilience procedures worked (was Starlink down?), and they reported the incident in compliance to EU CER and NIS2.
Either way, I'm sure they'll get an audit for EU CER compliance now, which will create a list of mandated immediate actions...
When those people aren’t around Bulgaria is incredibly peaceful country.
You install gates, raise walls, limit access, hire personnel, etc.
The more you need to secure whatever it is, the more layers you have.
In general, any respectable warehouse would have an external wall with a single entrance to the parking, and then a second entrance to the building itself.