HA cluster down

My HA cluster is down and I need help to figure out why.
Http, Asterisk down on both nodes, Floating IP down as well.
Any idea what could be happening?

This is PCS status:
[root@freepbx-a ~]# pcs status
Cluster name:
Last updated: Sat Oct 3 13:49:17 2015
Last change: Fri Sep 4 11:57:37 2015 via crm_attribute on freepbx-a
Stack: cman
Current DC: freepbx-a - partition WITHOUT quorum
Version: 1.1.10-14.el6-368c726
2 Nodes configured
20 Resources configured

Online: [ freepbx-a ]
OFFLINE: [ freepbx-b ]

Full list of resources:

spare_ip (ocf::heartbeat:IPaddr2): Started freepbx-a
floating_ip (ocf::heartbeat:IPaddr2): Stopped
Master/Slave Set: ms-asterisk [drbd_asterisk]
Stopped: [ freepbx-a freepbx-b ]
Master/Slave Set: ms-mysql [drbd_mysql]
Masters: [ freepbx-a ]
Stopped: [ freepbx-b ]
Master/Slave Set: ms-httpd [drbd_httpd]
Stopped: [ freepbx-a freepbx-b ]
Master/Slave Set: ms-spare [drbd_spare]
Masters: [ freepbx-a ]
Stopped: [ freepbx-b ]
spare_fs (ocf::heartbeat:Filesystem): Started freepbx-a
Resource Group: mysql
mysql_fs (ocf::heartbeat:Filesystem): Started freepbx-a
mysql_ip (ocf::heartbeat:IPaddr2): Started freepbx-a
mysql_service (ocf::heartbeat:mysql): Started freepbx-a
Resource Group: asterisk
asterisk_fs (ocf::heartbeat:Filesystem): Stopped
asterisk_ip (ocf::heartbeat:IPaddr2): Stopped
asterisk_service (ocf::heartbeat:freepbx): Stopped
Resource Group: httpd
httpd_fs (ocf::heartbeat:Filesystem): Stopped
httpd_ip (ocf::heartbeat:IPaddr2): Stopped
httpd_service (ocf::heartbeat:apache): Stopped

Failed actions:
drbd_asterisk_promote_0 on freepbx-a ‘unknown error’ (1): call=151, status=complete, last-rc-change=‘Sat Oct 3 12:11:36 2015’, queued=15142ms, exec=0ms
drbd_httpd_promote_0 on freepbx-a ‘unknown error’ (1): call=145, status=complete, last-rc-change=‘Sat Oct 3 12:11:36 2015’, queued=15144ms, exec=0ms

Got the cluster back up, but I am left with this error:
"Alerting is not available due to the ‘clustermon.sh’ script not being present on this machine"
Is that a problem?

This sounds like someone has added a firewall to that cluster.

The machines must have unfiltered access between each other. The error about unable to verify clustermon also signifies this.

I ran a health check and the clustermon error changed to:

“Warning: Clustermon.sh on the other machine is different to the version on this machine.”

As I said, that means that someone has been messing around with a firewall on that cluster.