The National Weather Service confirmed Wednesday that a single monster tornado that followed a nearly 150-mile path is to blame for 10 deaths over the weekend in Mississippi.

It was initially unclear if a single massive twister, or multiple smaller ones, caused the deaths and damaged nearly 700 homes in the state.

The state’s chief Weather Service meteorologist, Alan Gerard, said Wednesday that the tornado followed a nearly 150-mile track from Tallulah, La., through Mississippi, before dissipating in Oktibbeha County in northeastern part of the state.

Gerard said the tornado was unusually large — measuring 1.75 miles wide — a record for Mississippi.

The storm system went on to Alabama, where it spawned more tornados, and was blamed for two other deaths.

The storm’s track was the fourth-longest in the Mississippi history. The longest track was a 203-mile twister on March 3, 1966, at Candlestick Park in Jackson. The F-5 tornado killed 57.

Gerard’s comments came during a news conference Wednesday at the Mississippi Emergency Management Agency headquarters in Pearl.

Officials say tornado was the ninth deadliest in the state.

“This storm had everything going for it that we know to produce strong and deadly tornados,” Gerard said.

Damage was reported in 17 counties from Saturday’s tornado. Gov. Haley Barbour on Tuesday asked President Barack Obama to declare Yazoo and Choctaw counties major disaster areas, which would allow people there to apply for federal financial assistance, if granted.

State and federal officials are still assessing damage in other counties, but MEMA deputy director Lea Stokes said more information had been forwarded to Washington and more areas could be added to the declaration request.

Barbour said it’s the worst storm the state has had since Hurricane Katrina nearly five years ago.

The tornado injured at least 49 people and damaged about 700 homes in Mississippi, with the biggest destruction in Yazoo, Choctaw and Holmes counties.

Gerard said a significant weather system was forecast for this weekend, bringing thunderstorms, heavy rainfall and possible flooding.

“It doesn’t look like as violent a situation as it was last weekend,” he said.

Meanwhile, cleanup continued in affected areas.

Holmes County Sheriff’s Department Chief Deputy Roosevelt March said supervisors were working to get shelter, food and water to residents in need. The tornado killed one person in the county.

“Every day we’re finding new people who need help. The roads were so bad they couldn’t get through,” he said.

March said Wednesday was the first day he could get through the debris to people in need on the east side of the county.

“Everybody seemed to be alright,” he said.