Objectives: Ensure early identification and timely management of patient deterioration as essential components of safe effective healthcare. Prompted by analyses of incident reports and deterioration events, a multi-component organizational rescue from danger system was redesigned to decrease unexpected in-patient deterioration. Design: Quality improvement before-after unblinded trial Setting: 430 bed Canadian community teaching hospital Participants: All admitted adult medical-surgical patients in a before-after 12-month interventional study Intervention: Locally validated checklist (Modified Early Warning Score-MEWS + urinary catheter in-situ + nurse concern) with an intentional pause and explicit management options was deployed as a modification of an existing ward transfer of accountability fax report in the ED Results: Following deployment of ER-STOP, the risk of an unexpected CCRT (Critical Care Response Team) response within 24 hours of admission from ED to adult medical and surgical wards was significantly decreased (OR: 4.1, 95% CI: 2.17 – 7.77). Mean (+SD) ED wait-times (5.66+1.54 vs. 5.74+1.04 hours, p=0.30), ICU admission rate (3.84%, n=233 vs. 4.61%, n= 278, p=0.06) and cardiac care unit admission rate (9.51%, n =577 vs. 9.60%, n=579, p=0.198) were unchanged. Conclusions: ER-STOP improvement was out of proportion to the predictive value of the checklist component suggesting that effectiveness of this low cost sustainable tool was related to increased situational awareness, empowering a culture of patient safety and repurposing of an adjacent ED medical short stay unit use. Local adaptation within existing processes is essential to successful safety outcomes