Houston is being inundated with "unprecedented" flooding after the ferocious Hurricane Harvey set in over the Texas Gulf Coast this weekend, dumping torrential rain on the city with no end in sight for days.
"This event is unprecedented & all impacts are unknown & beyond anything experienced. Follow orders from officials to ensure safety," The National Weather Service (NWS) said Sunday morning.
The massive amounts of flooding comes after the hurricane, which has now left at least 3 dead after it bashed the Texas coast, left buildings and parts of communities submerged. In Houston, there were more than 1000 calls for rescues and people were forced to their rooftops.
A third death was confirmed Sunday by La Marque, Texas Mayor Bobby Hocking. The body of a 52-year-old man was found at the Walmart on I-45. La Marque is about 38 miles southeast from Houston on the Gulf Coast.
"At this time it is unknown if the subject passed away from health conditions or due to drowning, there was high water in the area of Walmart last night," the La Marque Police Department said in a statement.
The National Hurricane Center said at least 50 inches of rain has fallen in some areas, and one meteorologist estimated some 340 billion gallons of rainfall inundated the area.
Meteorologist Travis Herzog, who works for ABC affiliate station KTRK, estimates that 340-370 billion gallons of rainwater has fallen so far, which exceeds other major flooding events that have affected the region in recent years by over one hundred billion gallons.
President Trump tweeted about the storm this morning, saying that "experts are calling #Harvey a once in 500 year flood," but that the U.S. had "an all out effort going" in response to it.
One person died in Houston as a result of the flood, the city's police chief, Art Acevedo, confirmed late Saturday, marking the second confirmed death from Harvey.
"Sadly we have lost one female member of our community who encountered floodwaters in her vehicle, got out and was swept away," Acevedo said. "We also have reports of one other brutality but have not confirmed it."
Officials said another person died in the coastal city of Rockport.
Though Harvey weakened to a tropical storm by Saturday afternoon, southeast Texas -- particularly Houston -- continued to be hammered by the storm into Sunday morning.
More than 1,000 people were rescued overnight from the treacherous flooding in the Houston area, the NWS reported.
On Sunday, the NWS announced flash flood emergency situations for 12 counties in southeast Texas.
A bulletin said, "This is a flash flood emergency from the Bay City area to Wharton to Waller across the Houston Metro area to Stafford to Friendswood to League City and Santa Fe. Travel across the area is severely hampered if not impossible. Over 1,000 high water rescues have been performed and in some places emergency crews cannot reach the worst hit areas."
The NWS urged residents Sunday morning, "Move to higher ground now. This is an extremely dangerous and life-threatening situation. Do not attempt to travel unless you are fleeing an area subject to flooding or under an evacuation order."
Emergency services in Houston are being pushed to the limit. The city tweeted, "911 services at capacity. If u can shelter in place do so, a few inches in your home is not imminent danger. Only call if in imminent danger."
ABC affiliate KTRK tweeted the below photo of a viewer stuck in an attic with their children.
At a press conference Saturday night, Houston Mayor Sylvester Turner said, "It's a serious storm. It's going to last four or five days -- and today is day one." He urged residents to refrain from driving.
"Heavy rain band stalled over city for several hours, get off the roadways now," Acevedo tweeted Saturday night. "Use extreme caution flooding is widespread on roads."
And those who did not heed the aforementioned warning found themselves stranded. "In the last 10 mins we have gotten several calls of people stranded on the roads," Turner tweeted Saturday night. "Please help us keep you safe and help 1st responders."
Because of heavy rainfall, Sylvester at the press conference said several rivers were rising above banks. Homes in the west part of the city were also experiencing flooding, he said.
The city's public transportation agency announced Saturday night that it was suspending all bus and rail service.
Flooding was also reported in the area around Hobby Airport.
The devastating scene in Houston did not comes as surprise to residents, though. Texas Gov. Greg Abbott on Saturday warned of additional downpours forecast to drench already flooded communities in the coming days.
"Our biggest concern is between 20 and 30 more inches of rain in areas ranging from Corpus Christi over to Houston," Abbott said at a press conference. "We want to do everything we possibly can to keep people out of rising water."
Abbott said search-and-rescue missions and cleanup efforts have already begun in some parts of Texas, after Harvey slammed into the state's Gulf Coast Friday night as a Category 4 hurricane, unleashing a dangerous wrath of torrential rain and 130 mph winds. By Saturday afternoon, Harvey had gradually downgraded to a tropical storm as maximum sustained winds dropped to 60 mph by the evening, but the National Weather Service still warned of a "serious flooding event unfolding" inland over Texas, as well as "torrential rains."
Abbott, who visited with evacuees from the Corpus Christi area in San Antonio, said the displaced residents he met are in "strong" spirits despite the damage done and the ominous forecast.
"They are what I call typical Texans. They were resilient, they were strong, they were strong-spirited, they were happy," he told reporters at the press conference Saturday afternoon. "They were just happy to be there and be alive."
But Harvey has already proven to be deadly. In Rockport, one person was confirmed dead Saturday afternoon as a result of the storm, and more victims are likely, officials there said.
Although Harvey is projected to churn over southeastern Texas through the weekend, residents in hard-hit communities re-emerged Saturday to assess the damage and risk their lives to save others after a tumultuous night of rain, wind and reported tornadoes.
Here's what you need to know about the strongest storm to hit the Lone Star State in decades:
What's ahead: More rain, flooding, tornadoes
Texans expect a great deal more rain as the storm lingers over the region as it meanders between Victoria and San Antonio through the weekend.
"We are still expecting 25 to 30 inches [of rain] across southeast Texas," ABC News Meteorologist Daniel Manzo said Saturday. "This is in addition to what has already fallen this morning."
Flash-flood watches and warnings were in effect Saturday for much of southeastern Texas. Around 40 inches of rain is expected in some areas.
The forecast track shows Harvey heading back toward the coastline and interacting with the warm waters of the Gulf Coast early next week. This means areas that were already hit hard along the Texas coast should expect even more rain and wind, setting the stage for potentially catastrophic flooding.
Harvey is projected to take off Wednesday heading northeast and moving further inland into Texas, but staying west of Houston.
The storm is an evolving system, and its track could change.
Tornadoes are also a concern as there is a high risk of them in the region.
ABC affiliate KTRK-TV in Houston reported that a possible tornado was spotted in Texas' Fort Bend County. KTRK also reported tornado damage to as many as 50 homes in Missouri City.
At 4 p.m. local time, a tornado was confirmed near Cypress as well.
The full extent of injuries in Texas overnight remains unclear. Around midnight local time, Rockport City Manager Kevin Carruth said a total of 10 people were being treated for injuries stemming from Harvey.
Among the wounded were those at a senior housing complex, where the roof collapsed. Rescuers were able to transport the injured to a local jail that was serving as a makeshift medical center, Carruth said.
Abbott said at the press conference Saturday afternoon that he could not confirm any fatalities from the storm. However, officials later confirmed that one person was dead in Rockport as a result of the storm.
In Rockport, some 31 miles northeast of Corpus Christi, the city manager told ABC News that multiple buildings had been damaged, including the courthouse and the public school. The coastal community experienced peak wind surges of more than 125 mph overnight, according to the National Weather Service.
Meanwhile, images out of Corpus Christi showed flooded streets, destroyed buildings and debris.
In Missouri City, a reporter with KTRK tweeted photos of downed trees and houses without roofs.
In Fort Bend County, Major Chad Norvell of the sheriff's office tweeted, "Confirmed roof torn off by possible tornado on Vieux Carre in Sienna. Minor injuries reported."
A subsequent tweet said, "Minor damage to other homes in Sienna. Trees down."
In Victoria, an Exxon station was also damaged by severe winds, and street signs were strewn across thoroughfares.
How officials are responding
At Abbott's request, Trump on Saturday issued a major disaster declaration that immediately allows federal aid to flow to Texas' state and local recovery efforts in areas affected by Harvey. This means residents, cities and counties can begin the "rebuilding process" as quickly as possible, Abbott said.
Abbott has issued a proclamation waiving hotel taxes and state park fees for evacuees and first responders anywhere in Texas affected by the storm.
By Saturday afternoon, some 1,000 personnel had been assigned to search-and-rescue operations across Texas and the state's military department had deployed more than 1,800 service members to assist in responding to Harvey's aftermath. The state's public safety department had also assigned 80 troopers to the Corpus Christi area to assist in law enforcement needs, Abbott said.
Texas' transportation department had 228 buses ready to move evacuees to safety. More than 100 bus trips were already made by Saturday afternoon, Abbott said.
"It was so heartening to shake the hands of these evacuees as they got off these buses," the Texas governor said at a press conference. "They were just happy to be alive."
Meanwhile, the Coast Guard responded to "vessels in distress" near Port Aransas on Saturday morning, after its Corpus Christi sector received "mayday notifications from crewmembers aboard the tugboats Belle Chase, Sandy Point, and Sabine Pass."
Two MH-65 Dolphin helicopter aircrews were deployed from the Coast Guard's air station in Corpus Christi to assist the rescue.
"As information continues to come into the Coast Guard, we continue to monitor and respond to any situations for safety of life at sea," Capt. Tony Hahn, commander of Coast Guard Sector Corpus Christi, said in a statement Saturday morning.
Aircraft were also deployed from Corpus Christi "to conduct patrols and assess damage" in the area with the intent of reopening the port of Brownsville, the Coast Guard said while urging Texas residents to "stay safe and not venture out while storm damage is assessed." Other crews in shallow-draft vessels, capable of responding in flooded urban areas, headed to parts of Texas and Louisiana.
In a tweet on Saturday, the president cheered on Federal Emergency Management Agency Administrator Brock Long saying, "You are doing a great job - the world is watching! Be safe."
According to Texas Rep. Blake Farenthold, Trump is planning to visit the state early next week.
FEMA is also "closely" monitoring the storm and "working around the clock to prepare and support" efforts on the ground, Brock said in a tweet Friday morning.
Storm preparations began earlier this week in both Texas and Louisiana. As of Saturday afternoon, FEMA had amassed more than 396,000 liters of water, 524,000 meals, 4,500 tarps and 53 generators at incident support bases and staging areas in Texas and Louisiana, should the states need them.
FEMA officials were also in New Orleans on Friday working to make sure the Louisiana city's pumps are functioning in anticipation of the 7 to 10 inches of rainfall expected there. The National Guard had also readied 500,000 sandbags, FEMA said.
According to Abbott, the American Red Cross had opened 21 shelters where 1,450 people displaced by the storm were staying as of Saturday afternoon, and 42 more shelters were on standby if needed. Officials were also in the process of getting food, water, ice and other supplies to communities in need and setting up staging areas so those supplies could be distributed.
A spokesperson for the American Red Cross told ABC News they also have hundreds of trained disaster relief workers in Texas as well as truckloads of kitchen supplies, tens of thousands of ready-to-eat meals and trailers packed with shelter supplies that include cots and blankets.