Ferreira and Klote published this hyperlinked article in 2011. It provides an excellent narrative on stairwell pressurization in high-rise buildings. Having investigated numerous fires where compromised stairwells led to multiple fatalities, I believe that smokeproof enclosure design is one of the most important issues that faces the fire protection engineer in both new and existing high-rise buildings. During a fire, the stairwell is the only way out, and as such, is a single point of failure (SPOF) in the life safety strategy. In new construction, this SPOF risk is reduced through the use of smokeproof enclosures in combination with layered fire protection to include early notification, fire suppression, and compartmentation. In existing building construction, this same layered approach is often not present, which can significantly increase the risk to occupants. Engineers performing due diligence assessments should consider whether the stairwell design includes a SPOF risk and identify the methods by which a building owner could mitigate these risks. After all, shouldn't occupants in existing high-rise buildings be afforded the same level of safety as those in new high-rise buildings?