Follow the verified order
- Obtain the Underpass Key during the pharmacy progression.
- Enter the Underpass using the key/progression.
- Continue through the meat-locker and chase sequence.
- On the return route after the one-way/open-from-the-other-side segment, look for the Box Cutter.
The common mix-up
The Box Cutter is not the tool needed to enter the Underpass. It comes later. The verified item description is also limited: it has poor or short range, limited durability, and can cut certain applicable obstacles, but no exact durability count or universal obstruction rule is established.