To be effective, a symbol of death must always be placed in plain sight and in a prominent location.
Magic traps such as symbol of death are hard to detect and disable. A rogue (only) can use the Search skill to find a symbol of death and Disable Device to thwart it.
While this is the standard wording for a magic trap, I can't see how it would take a DC 33 Search roll to find a trap that only works if it can be seen from 60' away. The only interpretation I can think of that makes sense is a Rogue searching a square more than 60' from a symbol and noticing that if they enter that square they would see the symbol(and possibly activate it, if reading is the trigger) i.e. a Rogue can Search and Disable the "60' radius trap" centred on the symbol itself?