From USPS News Link:
Acting Customer Services Manager Tanya Jackson and Lead Retail Associate Leon Livengood were recently on duty in Portland, OR, when a customer experienced a medical emergency.
When Livengood noticed that the customer was in distress, he requested assistance from Jackson, who found that the woman was turning blue, had stopped breathing and had no detectable pulse.
While 911 was called, Jackson lowered the customer to the floor and performed CPR.
Emergency responders soon arrived and took the customer to a hospital.
The woman is recovering from the incident.