Google translate of the first tweet (in German):

> Extreme nightcap in the #network frequency. Quite unusual at this height and at this point in time. One of my measuring devices even shows 49.74Hz as a minimum. Has a major #power plant failed somewhere?

And second tweet:

>Here is another representation of the # mains frequency from just now. Extremely unusual, as a malfunction is to be suspected. Unfortunately, none of my network analyzers are currently running to check the exact course.