Torrential overnight rainfall flooded a handful of North Texas towns Monday, killing at least four people and stranding residents and their pets on the roofs of their homes.

A 5-year-old girl and her grandmother were swept to their deaths after the family's mobile home was carried off its foundation and lodged against a bridge above a swollen creek in this city along the Oklahoma border, said Cpl. Mike Linnell of the Texas Department of Public Safety. Divers were searching for the girl's sister, while the mother was pulled to safety.

In Haltom City, a Fort Worth suburb, a 4-year-old girl died after she was swept away by rushing water. Alexandria Collins' body was found more than two hours later.

The girl's mother, Natasha Collins, told KXAS-TV of Dallas that the last time she saw her daughter was "when the current took her out of my arms. We reached the boat, and the boat capsized."

However, firefighters said the girl was already missing by the time they pulled her mother onto a boat. Lt. Kent Worley, a spokesman for the Fort Worth Fire Department, said that boat never capsized and he didn't know of other boats involved in the rescue.

A woman died in Sherman, about 60 miles northwest of Dallas, after her car stalled in rising water and was swept away, Sherman police Sgt. Bruce Dawsey said.

About 125 residents of a Sherman nursing home were evacuated, and an unknown number of people were rescued from an office building where the roof started caving in, Dawsey said.

In Gainesville, aerial video showed families awaiting rescue on their roofs, some having hacked their way to the outside from their attics. Some were joined by their dogs. Three mobile homes were washed out of the park.

About 500 homes were flooded in and around the city. At one point, about 450 displaced residents had sought refuge at two temporary shelters. That number dwindled throughout the day as many arranged to stay with friends and relatives.

About 100 mobile homes in Haltom City were inundated and many were washed off their foundations, emergency officials said.

"When I looked out the window, water was up to the bottom of the window and the current was so fast houses were washing away, said Haltom City resident Rachel Hawkes. "You could hear people screaming but we couldn't get out to help."

About 37,000 people live in Sherman and about 16,500 in Gainesville.

Amtrak's daily round-trip service between Oklahoma City and Fort Worth was canceled because of flooding, and passengers were placed on buses, said Joe Kyle of the Oklahoma Department of Transportation. Fort Worth-based Burlington Northern Santa Fe, which owns the rail line, will decide when service can resume, Kyle said.

Authorities closed Interstate 35 from Gainesville to the Oklahoma state line for several hours because of flooding, the Department of Public Safety said.

The National Weather Service said rain fell at a rate of an inch every 15 minutes in some places early Monday.

"We get heavy rains in North Texas, but the rate, the amount, the duration and the coverage of this are just amazing," said Gary Woodall, the warning-coordination meteorologist for the weather service office in Fort Worth.

Only isolated thunderstorms were forecast in the area Monday and Tuesday.

Torrential rains also flooded creeks and rivers across central and southern Oklahoma, sweeping a truck off a bridge near Ada and forcing the evacuation of some homes in Caddo. Rescue workers plucked several people from vehicles trapped by rising floodwaters. As much as 3 to 6 inches of rain fell in some areas, and the National Weather Service issued a flash flood warning for seven counties on Monday.