HOUSTON ― Thousands of people awaited rescue on Monday as heavy rains poured into the area surrounding the nation’s fourth-largest city, worsening one of the most dramatic flooding disasters in recent U.S. history.

Over 30 inches of rain have fallen in some parts of southeast Texas since Hurricane Harvey made landfall near Rockport on Friday evening, shattering several previous rainfall records, leaving at least 300,000 people without power, and causing damage that authorities predict will take years to fix.

The death toll rose on Monday to at least nine, after Texas officials reported to The Washington Post that six people died in Harris County and authorities in Montgomery County stated that a falling tree killed a woman after landing on her home. Two other victims were confirmed over the weekend.

Many highways and streets throughout the region are flooded, making normal travel impossible and forcing first responders to rescue more than 2,000 people over the weekend, with more expected throughout the week. Houston Police Chief Art Acevedo said the department’s first priority was to complete 185 critical rescues with help from the 4,000 National and State Guard members activated for storm aid.

Texas Gov. Greg Abbott (R) announced on Monday that he had activated the state’s entire National Guard to help with disaster relief, increasing the total number of guardsman deployed to about 12,000.

Abbott said during a press conference later on Monday that the process of responding to the storm is only just beginning.

“This is a place that Texas and FEMA will be involved for a long, long time. We will be here until we can restore this region as back to normal as possible,” Abbott said.

“We need to recognize that it’s going to be a new normal ― a new and different normal for this entire region.”

The government also issued a mandatory evacuation order on Monday for several areas of Fort Bend County, southwest of Houston.

More flooding is ahead for the Houston region, forecasters warn, and an already dire situation could soon become desperate: An area the size of Connecticut is expected to receive at least another 20 inches of rain through Friday, though the rain is expected to let up intermittently through the week. Officials said that by the time the storm ends, Harvey could dump up to 50 inches of water on some parts of the affected area, which includes 54 counties.

Federal Emergency Management Agency Administrator Brock Long said he anticipates that at least 30,000 people in Texas will be displaced to temporary shelters.

“This is a landmark event for Texas,” Long said. “Texas has never seen an event like this.”

Lt. Zachary West/Army National Guard via Getty Images In this photo provided by the Army National Guard, a Texas National Guardsman carries a resident from her flooded home following Hurricane Harvey on Aug. 27 in Houston.

President Donald Trump on Monday declared a state of emergency for Louisiana, a year after floods devastated the region last August and 12 years after Hurricane Katrina made landfall in New Orleans. Up to 15 inches of rain were set to bear down on southwest and central Louisiana, with flash floods expected through Thursday.

“I want to stress that we are not out of the woods yet,” Acting Department of Homeland Security Secretary Elaine Duke said. “Harvey is still a dangerous and historic storm.”

Trump plans to travel to Corpus Christi, Texas, on Tuesday with first lady Melania Trump to visit some of the places most affected by the storm. Trump declared a state of emergency for many areas of Texas on Friday night, adding more counties on Sunday.

“I’ll be going to Texas tomorrow, I look very much forward to it,” Trump said on Monday. “Things are being handled really well. The spirit is incredible of the people.”

Houston resident Leidys Shull and 10 others, including children, remained trapped in her home Monday morning.

“Nobody has come to help us,” Shull said. “It’s just taking too long.”

Shull said she has seen only one boat come by in the hours since they’ve been stuck in the house.

“We tried to be a little bit calm, but we worry about the children,” Shull said. “I wish our local [officials] told us to evacuate. ... We had the possibility to leave, and now we are trapped inside our houses without food and running out of water.”

Adrees Latif/Reuters Residents use a truck to navigate through flood waters from Tropical Storm Harvey in Houston on Aug. 27.

Over 1,200 people were rescued in Harris County alone, Francisco Sanchez of the county’s Office of Homeland Security and Emergency Management told HuffPost.

Rescues and evacuations are ongoing, but Sanchez said most of the rescues relating to life-threatening situations have been completed. Volunteer civilian boats are also being dispatched to rescue people who are not in life-threatening situations and are requesting assistance.

“We cannot thank those people enough … it’s been phenomenal,” Sanchez said. “We were just taken aback by the sheer generosity by folks who stepped up.”

After initially being overwhelmed by the scale of emergencies, Sanchez said, the county currently has enough resources to meet its rescue needs.

Flood threat spreading farther east in Louisiana. Stay vigilant. #Harvey pic.twitter.com/Yw6v1choz3 — NWS WPC (@NWSWPC) August 27, 2017

As highway underpasses and feeder roads across Houston became lakes, first responders spent Sunday pulling people stranded from submerged cars into boats and plucking others from the rooftops of their homes by helicopter. Police also blocked roads to surrounding rural areas, where ranches and farms were under several feet of water.

Electric signs on Interstate 10 traveling east into the city read “High water” and urged drivers to “Turn around, don’t drown.”

Harvey is now stationary, and close enough to the water that it has an unlimited source of fuel, National Weather Service meteorologist Patrick Burke told HuffPost. The weather event will affect the area for “days, if not weeks,” he warned.

“If you’re sitting in the Houston area and you see a break and the rain lets up, don’t let your guard down. It’s gonna come right back in,” Burke said. “Rainfall predictions are as high as we’ve ever made for a storm.”

Officials urged residents trapped in their homes to avoid sheltering in their attics and to get on their roofs instead. “[H]ave reports of people getting into attic to escape floodwater,” Acevedo warned warned Sunday morning. “[D]o not do so unless you have an ax or means to break through onto your roof.”

Michael Wadler, 55, and his 17-year-old daughter watched with terror as their Houston home filled with water early Sunday morning.

“It bubbled up from the doors,” Maya Wadler told The New York Times. “Everywhere you turned there would just be a new flowing puddle. It just kept filling. It passed the outlets. I was so scared, we didn’t know what would happen.”

The pair were rescued around 4 a.m. Sunday and brought to a fire station, where Michael was able to get in touch with his wife and another daughter who were trapped at a neighbor’s house.

“This is truly apocalyptic,” Michael Wadler said.

Thomas B. Shea/AFP/Getty Images A submerged car is seen on Interstate 610 North on Aug. 27 in Houston as the city battles with tropical storm Harvey and the resulting floods.

Members of the Houston Fire Department were searching the interstate for both trapped drivers and bodies on Sunday afternoon. They commandeered a HuffPost reporter’s boat to look for a woman trapped in her car. When a rookie fireman asked if they would be recovering bodies, another explained they were only picking up survivors on that pass.

Long, FEMA’s administrator, appealed to the public for help in assisting federal rescue workers and requested volunteers to visit nvoad.org for more information on how to get involved.

“We need the whole community, not only the federal government forces,” Long said. “This is a full community effort from all levels of government and it’s going to require the citizens getting involved.”

Adrees Latif/Reuters Men use kayaks to get through an intersection after heavy rain from Hurricane Harvey flooded Pearland, in the outskirts of Houston, on Aug. 27.

Upstream and west of Houston, two giant reservoirs, built in the 1940s to protect the city from flooding, are already nearing capacity. The Addicks and Barker dams hold back the reservoirs’ collective 410,000 acre-feet of water and if the dams fail, half the city could be underwater. To prevent the structures from failing, the Army Corps of Engineers, which runs the dams, began releasing water from both the Addicks and Barker reservoirs before 2 a.m. on Monday, pouring even more water into the city.

David Lohr/HuffPost A submerged car in Katy, Texas, just west of Houston.

According to Houston city officials, more than 75,000 emergency calls have been made as of 9 a.m. Monday morning. On a normal day, 911 operators receive around 8,000 calls.

The city’s emergency services tweeted that they were at capacity and asked residents to only call if they faced imminent danger. The mayor advised people to give preference to life-threatening situations when calling 911.

Officials said the city’s public hospital, Ben Taub, was evacuated Sunday due to flooding and power outages. Later in the day, Bayshore Medical Center, another Houston metropolitan area hospital, decided to suspend operations and evacuate its 196 patients.

Houston Mayor Sylvester Turner has urged residents to prepare for days of heavy rains and flooding. During a news conference on Sunday morning, Turner advised residents to stay in place and said the city would be opening more shelters to cope with the storm’s effects. The city is opening its George R. Brown Convention Center as one such shelter, and Dallas will open a convention center that can host up to 5,000 evacuees on Tuesday morning.

“Just stay put,” Turner pleaded. “We need you to help us.”

Turner also told residents to refrain from driving and to “stay off the streets unless it’s an emergency.”

Still, many chose to ignore city officials’ recommendations to stay put, at times driving the wrong way up interstate exists in order to snake around flooded underpasses.

Roque Planas/HuffPost Rosanna Moreno looks over the flooded Buffalo Bayou on Interstate 610.

Rosanna Moreno, 55, had tried to reach the condominium building in the city where she lives after a family visit to the capital of Austin, only to find the expressway closed. She parked her car on Interstate 610, still several miles from the city, unsure of what to do next.

“People are crazy trying to go through,” Moreno told HuffPost. “Basically, we’re all underwater. We’re stuck.”

Lydia O’Connor, Nick Robins-Early, Dominique Mosbergen and Hayley Miller contributed reporting.

This is a developing story. Check back for updates.