HOUSTON (AP) -- With its flood defenses strained, the crippled city of Houston anxiously watched dams and levees Tuesday to see if they would hold until the rain stops, and meteorologists offered the first reason for hope -- a forecast with less than an inch of rain and even a chance for sunshine.
The human toll continued to mount, both in deaths and in the ever-swelling number of scared people made homeless by the catastrophic storm that is now the heaviest tropical downpour in U.S. history.
The city's largest shelter was overflowing when the mayor announced plans to create space for thousands of extra people by opening two and possibly three more mega-shelters.
"We are not turning anyone away. But it does mean we need to expand our capabilities and our capacity," Mayor Sylvester Turner said. "Relief is coming."
The rescues went on. Federal and local agencies said they had lifted more than 13,000 people out of the floodwaters in the Houston area and surrounding cities and counties.
Louisiana's governor offered to take in Harvey victims from Texas, and televangelist Joel Osteen opened his Houston megachurch, a 16,000-seat former arena, after critics blasted him on social media for not acting to help families displaced by the storm.
Meteorologists said the sprawling city would soon get a chance to dry out.
When Harvey returns to land Wednesday, "it's the end of the beginning," National Hurricane Center meteorologist Dennis Feltgen said.
Harvey will spend much of Wednesday dropping rain on Louisiana before moving on to Arkansas, Tennessee and parts of Missouri, which could also see flooding.
But Feltgen cautioned: "We're not done with this. There's still an awful lot of real estate and a lot of people who are going to feel the impacts of the storm."
The National Weather Service predicted less of an inch of rain for Houston on Wednesday and only a 30 percent chance of showers and thunderstorms for Thursday. Friday's forecast called for mostly sunny skies with a high near 94.
In all, more than 17,000 people have sought refuge in Texas shelters, and that number seemed certain to increase, the American Red Cross said.
The city's largest shelter, the George R. Brown Convention Center, held more than 9,000 people, almost twice the number officials originally planned to house there. The crowds included many from outside Houston.
By the end of the day, the Toyota Center, home of the NBA's Rockets, had begun accepting people who could not find space at the convention center.
Louisiana Gov. John Bel Edwards said he expected Texas officials to decide within 48 hours whether to accept his offer, which comes as Louisiana deals with its own flooding. About 500 people were evacuated from flooded neighborhoods in southwest Louisiana, Edwards said.
The city has asked the Federal Emergency Management Agency for more supplies, including cots and food, for an additional 10,000 people, said the mayor, who hoped to get the supplies no later than Wednesday.
In an apparent response to scattered reports of looting, the mayor also imposed a curfew. Police Chief Art Acevedo said violators would be questioned, searched and arrested.
Four days after the storm ravaged the Texas coastline as a hurricane, authorities and family members have reported more than a dozen deaths from Harvey. They include a woman killed when heavy rain sent a large oak tree crashing onto her trailer and another woman who apparently drowned after her vehicle was swept off a bridge.
Houston police confirmed that a 60-year-old officer drowned in his patrol car after he became trapped in high water while driving to work. Sgt. Steve Perez had been with the force for 34 years.
Six members of a family were feared dead after their van sank into Greens Bayou in East Houston. A Houston hotel said one of its employees disappeared while helping about 100 guests and workers evacuate the building.
Authorities acknowledge that fatalities from Harvey could soar once the floodwaters start to recede from one of America's largest metropolitan centers.
A pair of 70-year-old reservoir dams that protect downtown Houston and a levee in a suburban subdivision began overflowing Tuesday, adding to the rising floodwaters.
Engineers began releasing water from the Addicks and Barker reservoirs Monday to ease the strain on the dams. But the releases were not enough to relieve the pressure after the relentless downpours, Army Corps of Engineers officials said. Both reservoirs are at record highs.
The release of the water means that more homes and streets will flood, and some homes will be inundated for up to a month, said Jeff Linder of the Harris County Flood Control District.
Brazoria County authorities posted a message on Twitter warning that the levee at Columbia Lakes south of Houston had been breached and telling people to "GET OUT NOW!!" Brazoria County Judge Matt Sebesta said residents were warned that the levee would be overtopped at some point, and a mandatory evacuation order was given Sunday.
The levee was later fortified, but officials said they did not know how long the work would hold.
Officials in Houston were also keeping an eye on infrastructure such as bridges, roads and pipelines that are in the path of the floodwaters.