ST. THOMAS -- St. Thomas is one of the U.S. Virgin Islands under a warning as Hurricane Maria approaches, and it hasn't even begun to recover from Hurricane Irma.

Unless you're with the military, the only way to get to St. Thomas now is by boat or helicopter, CBS News' David Begnaud reports.

Close to the airport, the vast devastation from Irma was evident, and an elderly woman was being evacuated.

Jacob Bradley, an emergency response technician from Arkansas, said all the critically ill patients are being airlifted out of the hurricane's path.

"It's been bad. We've had six people laying in a restaurant because we couldn't get them to a hospital," Bradley said.

Even Bradley and other first responders are leaving.

"I would say it compares to Katrina, definitely, if not worse," Bradley said.

A lot of people around the island said, "Listen, I stayed for Irma, I'm gonna stay again for Maria." But CBS News also came across groups of people who said there's no way they're riding out another storm.

"It's horrible over there. There's not a leaf, every tree is bent, buildings, houses, businesses -- everything is devastated," resident Dana Neal said.

Some, like Ken Roy, aren't leaving.

St. Thomas was under a warning Monday night as Hurricane Maria approached. CBS News

"We have paradise, but this is what we have to go through," Roy said. "Been here before, done it before, and we'll do it again.

Chelsea Cesaro and her boyfriend, Breedy, have been trying to find a way out for two days.

"I'm just desperate to get out of there so I'm just trying to be as patient as possible, but it's hard not to give up," Cesaro said.

CBS News' Begnaud made it back to Puerto Rico and was warned that if Maria makes a direct hit, it could cut power to the island for weeks.

On Monday night, officials imposed food rationing of basic items like water, milk, baby formula, flashlights and batteries.