(CNN) -- A burst of intense rain caused perilous flash flooding Monday in parts of Louisiana, spurring the rescues of hundreds -- from people marooned inside their homes to middle school students stranded on a bus.
According to the National Weather Service, southern Louisiana was pelted with an estimated 15 inches of rain in six hours, with on-and-off rain continuing for hours after that.
"I'm 46 years old, native to this area, and have been through several hurricanes, and I've never seen anything like this," said Lafayette Parish Sheriff's Office spokesman Kip Judice.
Hours after the biggest pocket of rain hit, Judice said that 10 rescues were under way around 6:30 p.m. This is in addition to the more than 150 such operations that took place earlier to get people out of residences and cars.
One of those involved 16 adolescents whose bus became stuck after more than 4 feet of water covered the road, said Judice. Boats and dump trucks were used to reach the children and bring them to safety.
The town of Carencro was among the hardest hit communities in Lafayette Parish, according to Capt. Craig Stansbury, who is also from the Parish Sheriff's Office. He noted there were reports of water as high as 8 feet on some roadways.
Stansbury said fire department vehicles, tractors and conventional boats and air boats were being used to reach those stranded in homes and cars.
"A lot of things that we have at our disposal, we're just going to go ahead and utilize," he said. "Whatever it takes to get to the people."
One of the worst hit parts of the state was St. Landry Parish, where Government Administrative Director Jessie Bellard estimated 2,000 people had been affected so far. A state of emergency has been declared for the parish, though there are no known injuries or fatalities there or elsewhere.
People were driving dump trucks to rescue residents who have flooding in their homes and can't get out. He said several minor and major roads, including part of U.S. Highway 190, have experienced significant flooding.
"It's just a terrible situation," said Bellard.
Maj. Ginny Higgins of the St. Martin Parish Sheriff's Office said at least 15 to 20 roads were affected by flooding Monday in that parish. Several people were safely rescued after being trapped in their vehicles, she said.
A state of emergency has been declared for that parish, Higgins said.
Stansbury, from Lafayette Parish, said residents knew Monday would be wet but didn't foresee the volume or intensity.
"There was a forecast of some heavy rains, but I don't think anybody could have predicted that amount of rain," he said.
And while the worst precipitation is over, the headaches are not.
Intermittent rain continued to fall Monday, with the National Weather Service issuing a flash flood warning for all or parts of the parishes of Allen, Evangeline, Acadia, Lafayette, St. Martin and St. Landry through 11:30 p.m. The agency called conditions "dangerous ... with numerous roads and homes flooded."
Judice, from Lafayette Parish, said Monday evening that water levels were continuing to rise in his area.
"It's still a very crazy situation," he said.
CNN's Joe Sutton and Barbara Hall contributed to this report.