Part of the lawn yellowing and dying

[tjw1203]

Hi all, a part of my backyard lawn turned yellow and seemingly dead. What could be the cause? This part of the lawn gets the sun first in the morning, but not really sure if that is the reason. Thank you for your inputs!

 

[Oliver Buckle]

My first thought was 'dry', but then I saw the sprinkler, might still be worth making a small hole to be sure it is damp underneath, especially if that bit gets the sun.

 

[tjw1203]

My first thought was 'dry', but then I saw the sprinkler, might still be worth making a small hole to be sure it is damp underneath, especially if that bit gets the sun.

I will check. Thanks!