Why do I get System exit message once a week or so

Rails
1

On an average I get one or two error messages in a week. The complete
error
message is given below.

SystemExit: exit: SELECT * FROM cities WHERE (cities.id = ‘18’) LIMIT 1
On line #15 of app/views/postevent/venue.rhtml

12:
13:


14: State :
15: <%= City.get_state_name(@draft.temp_city_id) %> 16: 17: 18: City :
2

We used to have this problem when we were using fastcgi. Apache would
randomly kill some every now and again.

Fred