DES MOINES - Iowa Gov. Chet Culver said Tuesday he is deploying 165 members of the Iowa National Guard to help out in the wake of a fatal tornado that ripped through parts of northeast Iowa, killing seven and destroying more than 350 homes.

Those troops were on the ground in Parkersburg a short time after Culver's announcement. They relieved firefighters who have been working around the clock since the storm, according to Parkersburg Mayor Robert Haylock..

Their assistance is "really helpful and appreciated," the mayor said.

"We haven't seen anything like it since 1968, the Charles City tornado," Culver said at a press briefing Tuesday. "And we're still evaluating whether this was a level three, or level four (tornado), but it is clearly one of the most severe tornados that have ever touched down in the history of our state."

Culver said they would keep the curfew in place for the city of Parkersburg for reasons of public safety as residents sort through belongings and debris that can sometimes present hazards, such as propane tanks.

"We really want people to be very careful, and we want to protect the general public from any additional injuries or deaths," Culver said.

Authorities in Clarksville believe the Guard's presence will reduce the need for Parkersburg residents to rely on family and friends for help with cleanup. Power should be restored in the northern part of Parkersburg later today, Culver said.

Authorities were more restrictive Tuesday on the number of outsiders allowed to enter the town.

Officials were to again enforce an 8 p.m. curfew tonight.

With water restored in parts of the town, officials warned it may not be safe for consumption without boiling first.

Officials also issued a warning about possible food contamination due to loss of electricity since Sunday evening.

Guard members will help with debris removal, traffic control and deciding whether some damaged buildings are safe to enter. A total of 52 troopers with the Iowa State Patrol already are on the ground.

Culver thanked local officials and volunteers and other non-profit organizations for helping residents affected by the storms.

"The response that we've seen has been heartwarming in terms of those individuals and organizations that want to help in different ways," Culver said.

Dick Hainje, a regional director for the Federal Emergency Management Agency, joined Culver at the news conference, announcing that President Bush had declared Butler County a federal disaster area and signed a request for expedited federal services there.

"The people of Iowa are handling this situation extremely well," Hainje said.

Iowa officials added Delaware County to the state disaster list after damage was reported in rural parts of the county and flooding was reported in the Manchester area.

The county joins Butler, Buchanan and Black Hawk counties. FEMA began working with local and state officials this morning to complete damage assessments in those counties and could have an estimate of the total dollar amount of damages by the end of Wednesday, Culver said.

David Miller, director of Iowa's Emergency Management and Homeland Security Division, called the damage in the area widespread. Close to 40 people stayed Monday night at the Aplington Middle School, where the American Red Cross had set up a shelter.

A substantial nubmer of donated clothing items are avaible at the Aplington Elementary School for those in need, local authorities said.

Families, individuals and businesses affected will be eligible for assistance in the form of loans or grants, but Miller said most of the damages will be covered by insurance.

Those with damaged property were told to call their insurance companies first.

Disaster recovery centers will be set up in the coming days to give residents a "one-stop shop" for their needs, and Culver said they were working to find places for people to store belongings they were trying to save.

Culver said all steps were taken to notify residents of the coming storm, calling it a "blessing" the city of Parkersburg installed a siren just days before.

"If it weren't for that step, it would have been a lot worse. I think it also is an example of why these warning systems are so critically important for all 950 cities and towns in Iowa," Culver said, urging city officials across the state to invest in warning systems.

"Every second matters," Culver said. "We learned in this case … lives were saved because they were given adequate warning."

Culver said the state is "very interested" in helping the Aplington-Parkersburg school district after its high school was destroyed in the storm.

"We understand the pain and the loss with that high school, and so we're going to work together with the local officials and look at some options," Culver said, raising the possibility that the Iowa Legislature might be able to help the district out next session.

Charlotte Eby can be reached at 515-243-0138 or chareby@aol.com.

Storm damage by the numbers

Reported fatalities: 7

Estimated injured: 50, including one in critical condition Tuesday morning.

Homes completely destroyed: more than 350

Homes in Parkersburg completely destroyed: 288

Homes in New Hartford completely destroyed: 8

Homes in Hazleton completely destroyed: 15

Homes in Black Hawk County destroyed: 50

Homes with extensive damage: more than 100

Homes affected by flooding in Lamont: 240

Source: Iowa Gov. Chet Culver