mysql server stopped and i cannot restart

I am running 2.6.18-5-amd64

For some reason, the mysql server stopped and I cannot restart it. I have not upgraded and the machine was running nominally otherwise for 120+ days.

$cat /var/log/messages | grep mysql

Mar 21 12:04:57 localhost mysqld_safe[7775]: started
Mar 21 12:04:57 localhost mysqld[7778]: ^G/usr/sbin/mysqld: File '/var/log/mysql/mysql-bin.index' not found (Errcode: 13)
Mar 21 12:04:57 localhost mysqld[7778]: 090321 12:04:57 [ERROR] Aborting
Mar 21 12:04:57 localhost mysqld[7778]:
Mar 21 12:04:57 localhost mysqld[7778]: 090321 12:04:57 [Note] /usr/sbin/mysqld: Shutdown complete
Mar 21 12:04:57 localhost mysqld[7778]:
Mar 21 12:04:57 localhost mysqld_safe[7780]: ended
Mar 21 12:05:12 localhost /etc/init.d/mysql[7915]: 0 processes alive and '/usr/bin/mysqladmin --defaults-file=/etc/mysql/debian.cnf ping' resulted in
Mar 21 12:05:12 localhost /etc/init.d/mysql[7915]: ^G/usr/bin/mysqladmin: connect to server at 'localhost' failed
Mar 21 12:05:12 localhost /etc/init.d/mysql[7915]: error: 'Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)'
Mar 21 12:05:12 localhost /etc/init.d/mysql[7915]: Check that mysqld is running and that the socket: '/var/run/mysqld/mysqld.sock' exists!
Mar 21 12:05:12 localhost /etc/init.d/mysql[7915]:

I created a /var/log/mysql/mysql-bin.index file and gave ownership mysql:mysql. I have no idea if this previously existed or not, or, what information should be in this file.

Does anyone have suggestions? I've been reading all morning but haven't found anything helpful yet.

Harland