For 48 patients at Sebastian River Medical Center, memories of Hurricane Dorian are considerably more vivid than twisting palm fronds and big waves hammering the beach.

In the middle of the night, in what appears to be the first time in its 45-year history, Sebastian River evacuated its entire inpatient population as Dorian hovered over the Bahamas with winds as high as 200 mph.

It was one of eight hospitals in Florida that evacuated for the storm.

Starting around midnight on the Sunday before Labor Day, while the storm was still offshore and its path unsure, and continuing through Monday midday, a fleet of ambulances coordinated by the state took turns pulling into the bay of Sebastian River’s emergency department. Patients were brought down one by one, including some on stretchers, and sent to hospitals in Orlando and Melbourne.

Only Sebastian River’s emergency department stayed open, though doctors would have had to send patients elsewhere if they required hospitalization.

While Sebastian evacuated, Cleveland Clinic Indian River Hospital was activating a plan to remain fully operational during Dorian, with more than 400 people including patients staying at the hospital.

Both hospitals’ decisions followed the 5 p.m. posting Sunday of hurricane warnings for the Treasure Coast. Those were reduced to tropical storm warnings by Tuesday when the storm passed by offshore.

Sebastian River’s president Kyle Sanders said the evacuation was ordered as the window for transporting patients was coming to a close. That timeline was relayed by state emergency officials who had on standby a fleet of ambulances, as well as paramedics and EMT’s.

“It was mostly about that window closing and is it safe for the ambulances to be on the road," Sanders said. "The storm had not turned" north and was still headed for Vero, "and we were saying, when’s our last opportunity" to move patients out of harm’s way?

Beyond that window of opportunity, there were other windows to worry about – the ones in the hospital’s original building, which Sanders said “is not rated to withstand any category hurricane.” Built in 1974, the building includes the hospital’s main entrance as well as patient rooms, the cafeteria and five operating rooms.

While a 2010 addition has windows rated for a Cat 3 storm, and an addition scheduled to open in February should withstand Cat 5 storms, the process of retrofitting the main building can’t begin in earnest until the new tower is completed and patients and procedures can be relocated “in a domino effect,” Sanders said.

Steward Health has only had to stare down one other storm since buying Sebastian River in May 2017: Hurricane Irma, which ended up coming ashore in southwest Florida. Sebastian River stayed open during that storm, preparing for the worst with two full shifts of staff on hand, plus their families and pets.

Likewise, the hospital stayed open for every storm under two prior owners, including hurricanes Jeanne and Frances in 2004 and Hurricane Matthew in 2016.

The emergency department stayed open during the evacuation last week, but was not able to admit patients. The hospital was fully operational again by 7 p.m. Tuesday.

Sanders said the decision to evacuate ahead of Dorian was based on the ability of ambulances to be able to drive in increasing winds, as well as the hospital’s "location directly on the water in a low-lying coastal area put us at significantly higher risk for damage than other hospitals located more inland – including Cleveland Clinic Indian River."

The hospital is on the west side of U.S 1, sandwiched between the Indian River Lagoon, about a quarter mile east, and the Saint Sebastian River, which is only about 1,000 feet from the back of the hospital.

Despite its worrying proximity to so much water, the hospital was not in a county-mandated evacuation zone, unlike Cleveland Clinic Indian River in Vero Beach, which remained open despite its location east of U.S. 1 – the boundary of the evacuation zone.

While both hospitals date to the same era – the mid-1970s – Indian River has over time replaced the original windows with impact-resistant windows rated to withstand winds up to 150 mph.

In addition, the hospital’s six generators have been installed 41 feet above the flood plain, said Turner.

“We stayed with normal shift changes until the winds were high enough that the county closed the bridges and started the mandatory evacuation process,” said Indian River’s COO, Dr. Ralph Turner, who along with the hospital’s president, Dr. Greg Rosencrance, organized the hospital’s staff in teams to allow for their own homes’ hurricane prep as well as needed rest.

The emergency plan went into effect at 7 a.m. Monday. Throughout, some 260 Cleveland Clinic caregivers and 43 physicians had to be housed at the hospital during the storm, along with 150 patients.

“We had 96 hours of food on hand, 10 days of pharmaceuticals, 96 hours of fuel for six generators, and tankers ready to mobilize once we got the all clear,” recited Rosencrance by rote, days after the storm. “We had to be able to be self-contained and independent for five days.”

Pump trucks stayed on site to deal with possible flooding; technicians were there to maintain the generators; and ham radio operators and satellite phones were available should Internet and cellphones fail, as they did in the 2004 twin hurricanes, Frances and Jeanne.

When word came that deputies normally assigned to the hospital would be needed elsewhere during the storm, a special security detail was brought in. Cleveland Clinic dispatched four security officers who drove from Cleveland, Ohio straight through to Vero Beach. “They took turns driving and timed it so they arrived just before the weather started,” said Turner.

Their squad car, marked “Cleveland Clinic Police,” was parked outside the ER entrance through Wednesday.

As for storm damage to either hospital, it appears to have been confined to one spot at Indian River: Rosencrance’s office. “It flooded twice in 24 hours,” said Rosencrance. “The drainpipe leaked from a shower above.”