I have not idea what this mean:

 Tekmi yasiyacaksin orada!

Can someone help, please!

My Try:

Are you going to live there alone?

Thank you, but it should not be a question, so can someone else confirm this. 

Concept of this is: 

I said: Ben Londra gidiyorum bu aksam. 

And other side said this: Tekmi yasiyacaksin orada!

I confirm then

tek = one, alone, without any other.

yaşamak = to live, yaşayacaksın = you will live.

orada = there

Tek mi yaşayacaksın orada?

Does that sound good? Or maybe you would like to see more confirmations?

Abla´s translation is correct. And it is kind of question although it can be counted as "statement of suprise[shock, anger]" such as ;

I and my friend went out and when we came back home, she [who had house key] notices that she lost the key and when she tells me that she lost the key , I react her by saying ;

Anahtarları mı kaybettin ! ?  ---> did you lose the keys ?  or

                                              you lost the keys ?

there is an anger and shock in my voice when I make that statement. so it still is kind of question as I expect her to make an explanation of how she lost the keys.

Three Turks confirming it. This is my day.

Your translations normally don´t need a confirmation .