The blaze reduced the privately run Anderson Guest House to a skeleton of cinder blocks and stunned this rural community of about 1,800 people tucked in the Ozark hills of southwest Missouri.
Gov. Matt Blunt said investigators were treating the fire as suspicious.
"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," Blunt said.
The home had 32 residents and two employees inside when the fire was reported around 1 a.m. The dead ranged in age from early 20s to the elderly. Another 18 people were taken to hospitals and six were treated at the scene, authorities said.
Officials refused to say how the victims died or whether they had any warning of the flames. The home had fire alarms but no sprinklers.
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," the governor said. "That would impact to some degree the amount of care that is necessary."
Neighbor Betty Wood heard the screams and ran out to help. "You could just tell they were in shock. They just couldn't get their eyes off the fire," she told CBS News correspondent Lee Cowan.
Neighbor Steven Spears, 47, saw the blaze erupt through security cameras posted outside his home.
"I saw the front door blow open with fire," Spears said "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 was 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.
A Joplin hospital would not release the conditions of four people sent there after the blaze. Two people were in serious condition at a Springdale, Ark., hospital. All other survivors were either in good condition or had been treated and released from hospitals.
Authorities were trying to determine if the blaze was linked to a smaller fire at the facility Saturday morning, said Assistant Fire Marshal Greg Carrell. No one was injured in the first fire, which was still under investigation when the second blaze began.
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.
However, CBS News chief investigative correspondent Armen Keteyian reports that the operator of the ill-fated group home reportedly has been cited in recent years by the state of Missouri for the "most severe" violations of fire laws in two other facilities it runs.
In October 2003 the state found that Joplin River Of Life Ministries failed "to obtain an annual fire inspection" for its residential care facility in Carthage, and that staff members at another facility in Joplin placed "a pencil in the reset switch to prevent fire alarm activation."
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 Missouri Mental Health Task Force issued a draft report last month demanding far more protection inside all homes for the mentally disabled. The chief concern was the state's failure to follow its own rules in supervising operators of those homes, Keteyian reports.
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 for new employees as quickly as required by law. All the deficiencies were corrected within three weeks, according to the health department.
Monday's blaze was one of the worst fires at a health care facility since 2003, when a patient suffering from dementia and multiple sclerosis, set fire to her bed and burned down a care center in Hartford, Conn., killing 16 residents. Six months later, in September 2003, a fire killed 15 patients in Nashville, Tenn.
But the growth has not been without problems. CBS News reports that in New York, news reports of chronic abuse and neglect in adult homes prompted calls to overhaul the state system. In Kentucky, investigators recently found repeated instances of medication errors, inadequate staffing and poor sanitation. And back in Missouri, a recent investigation found in the last five years (2000-2005), there were 21 deaths, more than 300 injuries and almost 2,000 other incidents tied to abuse or neglect by caregivers.