exeng,
Staffing a facility with only one controller is NOT safe, but many facilities still do it, including many in the United States. The problem is what happens if this controller has a medical emergency, what happens if there is an accident on the field and now this controllers workload has climbed exponetially.
There have been documented cases where a controller did become injured or had a medical emergency and wasn't found until the next shift (morning crew) reported to work, luckily as far as I know no controllers have died during a one person shift.
Mike
NATCA FWA