What do I do when a student working in my lab "ghosts" me? I am in my first PhD year and have some teaching duties -- assisting my supervisor with his lectures and also advising students. At the beginning of the semester, a student started working on his Bachelor's thesis and initially everything was fine.

However, for several weeks now I have not received any response from him. I wrote him mails on a weekly basis asking for a status update and inquiring whether he was stuck. Now the deadline is getting closer and while he could make some progress during the first weeks, I am afraid it is too little to pass. On the other hand, I saw a quite familiar post on SE recently and I believe it is actually him, as the topic is quite specific. Therefore I assume he actually is still working on his thesis.

I already have escalated the issue to my supervisor and he told me to let it student fail if required. I am not too satisfied with this way of dealing with the situation. Are there other options for me?
I wrote him mails on a weekly basis asking for a status update and inquiring whether he was stuck. 


It seems that you are completing your duties as an advisor well. You can and should continue to offer help and suggestions in accordance with your duties. Perhaps this student is too busy or too anxious to respond to your emails. In that case, you could provide links to resources that might benefit them without the necessity of responding (if you feel that they need more advising).

While I personally try to respond to emails in a timely fashion, I often work better independently and only reach out when I am in need of assistance; this student might function the same way.


  I already have escalated the issue to my supervisor


Great, this means that your supervisor is aware of the issue and is likely to be understanding in the event that your student does not do well.


  he told me to let it student fail if required


This is also fine. If the student does not adequately complete their work, this is the expected outcome. If you are concerned that the student is unaware of this, you could send an email letting them know (or possibly reminding them of policies in the syllabus regarding this).


  Are there other options for me?


You cannot force the student to respond or work on their project. You should continue to advise this student to the best of your ability, but beyond that it is their responsibility to follow through.