State fire investigators were trying to determine Monday whether a fast-moving early morning blaze that killed 10 people and injured two dozen at a southwest Missouri group home for the elderly and mentally ill was deliberately set, Gov. Matt Blunt said.

"We're not saying it is definitely a crime scene, but we are treating it as if it is and trying to determine if the fire was set by somebody who had a nefarious motive," he said.

"It is being treated as a suspicious fire," he said, without elaborating about potential evidence.

Supervising Investigator Bill Zieres with the Missouri Fire Marshall's Office tells Fox News officials have pinpointed the ignition point in the northeastern part of the building. Zieres says they've found no physical evidence so far to indicate the fire was deliberately set. Zieres adds nothing has been ruled out and investigators are trying to keep an open mind to any possibility.

One thing investigators are checking out is a gas furnace and electrical wiring in the part of the building where the fire started.

The blaze, reported about 1 a.m. and brought under control just before sunrise, reduced the privately run Anderson Guest House to a skeleton of cinder blocks and stunned its namesake city, a former railroad town of about 1,800 people tucked in the Ozark hills about 35 miles south of Joplin.

Zieres says firefighters got on the scene very quickly but had a difficult time getting control of the fire, which quickly chewed through the wood roof of the building.

The home had fire alarms but no sprinklers, said Assistant State Fire Marshal Greg Carrell.

One of the dead was a worker in the home and the other nine were residents, Blunt said. Authorities had not yet released the names, pending notification of relatives.

"I saw the front door blow open with fire," said neighbor Steven Spears, 47, who was watching TV and saw the blaze erupt through security cameras stationed outside his home. "I know most of them (the residents). I've talked to all of them at one time or another. It still hasn't hit me."

The home is operated by Joplin River of Life Ministries Inc. A woman who answered the phone there said the firm would not immediately comment but might release a statement later Monday.

The dead ranged in age from early 20s to the elderly. Eighteen people were taken to area hospitals and six were treated at the scene. The home had 32 residents and two employees inside when the fire was reported around 1 a.m., Highway Patrol spokesman Kent Casey said.

Two people were in serious condition at a Springdale, Ark., hospital. Freeman Hospital West in Joplin would not release the conditions of four people sent there after the blaze. All the other survivors who went to area hospitals were either in good condition or had been treated and released.

Officials were refusing to say how the victims died or whether they had warning. Blunt also said authorities were still investigating whether the home's residents were in bed when the fire began.

Asked if two staff members were enough to look after 32 residents, Blunt said that was up to state health officials.

"Again, it was late at night," he said. "That would impact to some degree the amount of care that is necessary."

There also was no information to suggest any of the victims were originally from Anderson, a town of mostly small businesses and manufacturing and whose residents commute roughly an hour south to Wal-Mart headquarters in northwest Arkansas or the businesses that have sprung up around the retailing giant.

On Saturday, there was a mattress fire on the other side of the building. No one was injured in the first fire, which was still under investigation when the second blaze began. Investigators say there's nothing to indicate that the deadly blaze was a rekindling of the earlier fire.

Inspectors from the Missouri Department of Health and Senior Services, which licenses the facility, found some deficiencies at the home in March but none related to fire safety, agency spokeswoman Nanci Gonder said.

"This is a devastating situation and we express our sympathy to the families of those who were killed or injured in the fire," Gonder said in a news release.

The deaths were the most from a single blaze in Missouri in recent memory.

"It's terrible," Casey said. "I have never been involved in a fire in which 10 people lost their lives."

The home is a residential care center licensed by the Missouri Department of Health and Senior Services. The facility also has a license from the state Department of Mental Health that allowed mentally ill residents to live at the home and receive treatment elsewhere.

The facility was cited in March for grease buildup in the kitchen, uncovered fluorescent light fixtures, allowing meat to thaw on the kitchen counter instead of in a refrigerator, allowing a resident to take more than the prescribed dose of an inhaler and not requesting criminal background checks as quickly as required by law for new two new employees. All the deficiencies were corrected within three weeks, according to the health department.

In 2003, a patient suffering from dementia and multiple sclerosis, set fire to her bed and burned down the Greenwood Health Center in Hartford, Conn., killing 16 residents. Six months later, in September 2003, a fire killed 15 patients in Nashville, Tenn.

The Associated Press contributed to this report.