Houston officials — under fire for not calling for a mass evacuation before Hurricane Harvey triggered deadly flooding over the weekend — are defending their decision to tell residents to stay put.

"You literally cannot put 6.5 million people on the road. If you think the situation right now is bad, you give an order to evacuate, you are creating a nightmare," Houston Mayor Sylvester Turner said, according to Weather.com.

"With a rain event over a county of 4.5 million people, you don't know exactly where the rains going to fall, you don't know which neighborhoods are going to flood," Harris County Judge Ed Emmett told NBC's "Today" show.

"So if we had gone out three days before and said we want 4 million people to leave Harris County that would have been a totally nonsensical thing to do . . . The truth is, if we had told people to do that, they would have laughed at us or ignored it."

Harvey hit Texas late Friday as a Category 4 hurricane and has continued to pound the Lone Star State with punishing rains, even as it was downgraded to a tropical storm.

Before the storm is gone, some parts of Houston and its suburbs could get as much as 50 inches of rain — the highest amount ever recorded in Texas. The hurricane is said to have been responsible for at least five deaths.

Louis Uccellini, director of the National Weather Service, has warned that the catastrophic floods may worsen in the next few days before slowly receding as the storm clears.