如何在PHP中解决ERR_EMPTY_RESPONSE

I have a PHP script which has customer location listing and i use the below google maps script for updating location information using ajax calls

I get a error very few time like 'didn't send any data ERR_EMPTY_RESPONSE'

I checked for Chrome error and server error, but this error comes once in 10 time of page access , but removing the below script solves the problem.

<script async defer
src="https://maps.googleapis.com/maps/api/js?key=AIzaSyDc_ZBOMO44gX2LsdT-NSg_pKEBNeoI3hI">
</script>

Is there any solution where i can have the above map script and fix my page issue ? I use Js version 1.7.2