Kill-9 will not erase the process and Apache will not start.

$sudo systemctl start httpd.service

Job for httpd.service failed because the control process expired with error code.See "systemctl status httpd.service" and "journalctl-exe" for details.
[ec2-user@ip-w-x-y-zwww] $sudo systemctl status httpd.service
● httpd.service - The Apache HTTP Server
   Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled; vendor preset: disabled)
  Drop-In: /usr/lib/systemd/system/httpd.service.d
           --php-fpm.conf
   Active: failed (Result: exit-code) 
     Docs:man:httpd.service(8)
  Process: 3650 ExecStart=/usr/sbin/httpd$OPTIONS-DFOREGROUND (code=exited, status=1/FAILURE)
 Main PID: 3650 (code=exited, status=1/FAILURE)
   Status: "Reading configuration..."

: Starting The Apache HTTP Server...
: (98) Address already in use: AH00072: make_sock: could not bind to address [::]: 80
: (98) Address already in use: AH00072: make_sock: could not bind to address 0.0.0.0:80
: no listening sockets available, shutting down

systemd[1] —httpd.service failed.

 $sudolsof-i | grep http
nginx3109 root6u IPv4 185880t0 TCP*: http (LISTEN)
nginx3109 root7u IPv6 185890t0 TCP*: http (LISTEN)
nginx3110 nginx6u IPv4 185880t0 TCP*: http (LISTEN)
nginx3110 nginx7u IPv6 185890t0 TCP*: http (LISTEN)

$sudokill-93109

 $sudolsof-i | grep http
nginx3109 root6u IPv4 185880t0 TCP*: http (LISTEN)
nginx3109 root7u IPv6 185890t0 TCP*: http (LISTEN)
nginx3110 nginx6u IPv4 185880t0 TCP*: http (LISTEN)
nginx3110 nginx7u IPv6 185890t0 TCP*: http (LISTEN)