HOUSTON -- Relatives believe six family members died Monday while trying to escape the floods of.
A family member, who didn't want to give his name, told CBS News correspondent Mark Strassmann.
"The water took 'em, the water took 'em, they went into a ditch. My uncle got out, the National Guard came and tried to get the door open but couldn't. All my nieces and nephews drowned -- my grandpa, grandma," the man said Monday.
"Were you close to your nieces and nephews?" Strassmann asked.
"Yes, they're my babies, they're my babies," the man replied.
Witnesses told CBS affiliate KHOU-TV that the family's white van was driving down a street in Greens Bayou Sunday afternoon when it hit high flood waters.
The van's driver, the family's great-uncle, escaped the van before it submerged under water. He was able to crawl out of the vehicle and grab onto a tree limb.
The passengers included four children, ages 16, 14, 8 and 6. Their great-grandparents, ages 81 and 84, were also in the vehicle. The driver reportedly called out to them to try to get out through the back door, but they were unable to escape.
Witnesses said first responders were in the area, but were unable to rescue the passengers.
Authorities have not yet confirmed the deaths. But three relatives of the family confirmed the deaths to KHOU-TV on Monday.
Floodwaters reached the roof lines of single-story homes in some areas Monday and people could be heard pleading for help from inside as Harvey poured rain on the Houston area for a fourth consecutive day after a chaotic weekend of rising water and rescues.
The nation's fourth-largest city was still largely paralyzed by one of the largest downpours in U.S. history. And there was no relief in sight from the storm that spun into Texas as a Category 4 hurricane, then parked itself over the Gulf Coast. With nearly 2 more feet of rain expected, authorities worried the worst was yet to come.
Harvey has been blamed for at least two confirmed deaths.