For buildings and apartment complexes, they usually have a dedicated switch/line (I don't know the technical term). So, it's most likely that the cable got dam

For buildings and apartment complexes, they usually have a dedicated switch/line (I don't know the technical term). So, it's most likely that the cable got damaged due to bad weather (rainy season, laying out cable open to the sky), or the closest switch suffered a damage due to electricity fluctuations. These are the 2 main reasons for internet going down for that long. With me, it usually happens during a power cut. While I have UPS power backup and my router keeps running, it seems the local (geographical) area hub doesn't and internet goes down for 5 minutes.