The record-breaking flood waters, which have soaked much of Houston, are being blamed on a series of fires at a chemical plant in the city.
Fears over toxic fumes forced the evacuation of a nearby neighborhood on Thursday.
"Exposure to smoke from these organic peroxides is similar to standing over a burning camp fire," Harris County Sheriff Ed Gonzalez said.
Backup generators designed to keep the chemicals at proper temperatures failed, causing the chemical reaction.
The site was hit with much more water than expected.
In other areas across town, there were signs that water levels are going down.
When Local 10 News reporter Terrell Forney visited Buffalo Bayou Park earlier in the week, not a single walking trail was visible.
On Thursday, the trails were starting to emerge and so were the people.
"I walked that way and it's totally cut off, so I'm going to try this way," Angela Ahrendt said.
Tons of donated items are being collected and sorted for those who have been affected by Hurricane Harvey.
"Plain toiletries, blankets, pillows, water, food -- you name it. Everything has come in here," Juan Rodriguez, of BBVA Compass Stadium, said.
Donated items have filled the entire 22,000-seat stadium so much so that volunteers have had to turn folks away.
The man running the show is a Miami native.
"It's not over and, unfortunately, this is only the beginning of this recovery," Rodriguez said. "And South Floridians know (that) you do build back and you do it strongly, but you need everybody's help."