St Aubyn: Fourteen Hours Before Hurricane Delia

The binding constraint is transport and shelter capacity, not warning time. Four buses at roughly 50 people per trip can move about 200 per trip; with loading, congestion and driver rest, perhaps six or seven trips are realistic - roughly 1,200–1,400 people. Shelter space is 1,100. So the plan must be selective.

1. Hours 0–2 - activate and inform. Broadcast warnings, open both shelters, call in shelter managers, fuel buses, and pre-position water, food and tarpaulins.
2. Hours 2–6 - move priority groups. Use the two ambulances and two buses for the 60 dialysis patients, hospital patients who can be moved, the elderly, pregnant women and young children. These people cannot self-evacuate and dialysis interruption is life-threatening.
3. Hours 3–7 - move the 200 tourists. Visitors lack local knowledge, transport and family networks, and the three beach hotels sit squarely in the surge zone. Bus them to the school hall after shutters are fitted and sanitation is topped up.
4. Hours 6–9 - fill remaining shelter space with residents of the lowest coastal lanes, and broadcast addresses of surveyed two-storey reinforced buildings for vertical evacuation, since a 3–4 m surge will submerge single-storey houses.
5. Before hour 8 - shut the bridge. At 1.8 m it will be cut by the surge; no vehicle movement on that route afterwards.
6. Hours 9–14 - lockdown. Stop outdoor movement, account for shelter occupants, and prepare the helicopter for post-storm medical evacuation only.

The instruction is unworkable on three counts.

• Capacity: 1,800 people against 1,100 shelter places leaves about 700 with nowhere sanctioned to go. Sending them out would create unmanaged crowds in unsafe buildings, which is worse than a planned vertical evacuation.
• Transport: four buses and two ambulances cannot move 1,800 people in 14 hours, especially once the bridge is cut and roads flood. Evacuating on the last available vehicles puts people on the road exactly when the surge arrives.
• Special needs: hospital patients on dialysis cannot simply be bussed away; they need continuing treatment.

What should replace it: a phased, targeted message - 'if you are in zone 1 or 2, be at the shelter or a marked vertical evacuation building by hour 9'. That means:

• pre-identified, surveyed two-storey buildings above 4 m with capacity labels;
• zone maps broadcast clearly so people know whether they are in the surge area;
• priority transport allocated to those who cannot move themselves;
• an explicit instruction to stop moving after hour 10, because being outdoors in 165 km/h winds is more dangerous than sheltering in place.

The aim is to reduce deaths, not to achieve a complete evacuation on paper.

1. Critical facilities are located in the hazard zone. The hospital, airport and main road all sit below 3 m, where a 3–4 m surge will strike. Losing the hospital removes the island's main medical capability just as injuries occur, and losing the airport blocks the arrival of relief flights and supplies. A small island has no inland alternative, so a single siting decision converts a weather event into a medical and logistical emergency.

2. Limited coping and evacuation capacity. There is one high-ground shelter for 700 people against 1,800 in the coastal strip, plus four buses. The bridge at 1.8 m is a single point of failure that will be cut early. These are characteristics of the island's development, not of the storm.

A third, supporting factor is sensitivity of the population: 60 dialysis patients and 200 tourists (who have no local networks or transport) raise the proportion needing help. The 2004 precedent - 9 deaths and $40 million of damage - also shows a recovery burden that may still be constraining investment in defences.

Vulnerability therefore equals exposure plus poor access plus thin capacity; the hurricane only tests it.