According to the "Overvoltage Protection" section of the datasheet (Rev 2; 12/96), always sequence V+ on first, followed by VL, V-, and logic inputs. If VL is powered first, the voltage of VL will surpass V+, thus damaging the device.
The datasheet also states "If power-supply sequencing is not possible, add two small, external signal diodes in series with the supply pins for overvoltage protection (Figure 1). Adding diodes reduces the analog signal range to 1V below V+ and 1V above V-, without affecting low switch resistance and low leakage characteristics. Device operation is unchanged, and the difference between V+ and V- should not exceed +44V."