Harvey, which has now been downgraded to a tropical storm, hammered Texas as emergency crews rescue people from their homes and cars as the flood waters rise.
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The devastating photograph captured elderly people in a care home filled deep with water, rising above chairs and other furniture.
They are captured clinging onto their belongings in the image thought to be from La Vita Bella in Dickinson, Galveston County.
Many of the people who live there are believed to use wheelchairs and oxygen tanks.
Stranded vehicles in high water from Harvey
Firefighters put out a fire during the aftermath of Harvey on August 28
National guardsmen rescue stranded residents after the massive flooding
According to the New York Daily News, the trapped patients were airlifted to safety on Sunday.
Owner of the nursing home Trudy Lampson is believed to have sent flood photos to her daughter and son-in-law, Kim and Timothy McIntosh, in Florida, who then shared them on Twitter.
In a desperate caption, he wrote: "La vita Bella nursing home in Dickinson Texas is almost underwater with nursing home patients."
Incredibly in the photo, the people seem relatively calm.
But Kim McIntosh told CNN her mother had said it was a "disaster", revealing the water had become waist deep within just 15 minutes of it coming through the doors.
She also said that at first they were told first-responders couldn't reach the people inside.
Kim said: "That's when we decided to go ahead and tweet the photos, because we were afraid she wasn't going to get any help."
The Cove Harbor Marina & Dry Stack storage facility took severe damage from Harvey
Emergency workers and medical staff at a shelter in the aftermath
Some people online claimed the photo was fake, but Mr and Mrs McIntosh insist it's genuine.
Hours after it was posted online, the Galveston County Office of Emergency Management reportedly confirmed all the patients were safe having been airlifted out, and that the situation was 'resolved'.
At least two people have been killed while a further 1,000 people have been rescued from the Houston area alone.
And the death toll is expected to rise as the storm is predicted to continue to lash the state for several more days.
Harvey has caused chest-deep flooding on some streets in Houston as rivers and channels overflow their banks.
Flood victims at a shelter
The Coast Guard flood team on a flooded street
Some parts of the city have already seen up to 76 cms of rain while the storm is expected to dump 30-63cms more over the next few days, the National Weather Service forecast.
The total could reach 127cms in some coastal areas of Texas by the end of the week, or the average rainfall for an entire year.
"This event is unprecedented and all impacts are unknown and beyond anything experienced," the government's National Weather Service said on Twitter.