LASALLE, Ill. (NewsNation Now) — State officials are investigating a coronavirus outbreak at a veterans nursing home in rural Illinois that has infected nearly 200 residents and staff, and killed 27 veterans.

Illinois Gov. J.B. Pritzker’s office and the state’s Department of Veterans Affairs are attempting to determine what caused the outbreak at the state-run LaSalle Veterans Home in LaSalle, about 90 miles southwest of Chicago.

The department on Tuesday requested an independent probe into the facility, which was the focus of a state Senate committee virtual hearing on the outbreak.

“The tragedy of what has unfolded at the veterans’ home cannot be understated,” said state Sen. Sue Rezin, who represents the district where the home is located. “I’m glad that the director has called for an independent investigation and agree that there are lessons to be learned from this terrible outbreak that has claimed the lives of 27 of our nation’s heroes.”

The current outbreak was identified in late October when a staff member and a resident tested positive for the virus. Since the beginning of November, two-thirds of residents and employees have tested positive, according to the Illinois Department of Veterans Affairs (IDVA).

“November 4th, there were only four cases of COVID within the home,” Rezin said Monday. “Very quickly within the past 20 days, we’ve had almost 200 cases.”

Dr. Avery Hart, a consultant for the state’s public health department, said at the hearing that all 16 long-term care facilities in LaSalle County have had outbreaks.

“It is no coincidence that cases within the home began to rise just as cases rose dramatically within the surrounding community,” Veterans Affairs Director Linda Chapa LaVia testified Tuesday at the hearing.

“This virus attacks quickly,” LaVia said. “I feel our staff moved as quickly as they could.”

NewsNation affiliate WGN reported inspections revealed several issues at the home, including challenges with timely return of testing and breaks from protocol in coronavirus prevention and containment including wearing masks and social distancing.

Issues of short staffing were also a concern, including clear procedures on whether staff was required to work even though they tested positive for COVID-19, according to WGN.

State officials have increased staff testing at the facility, and the governor said an infection control team was sent to the home. As of Tuesday morning, 40 of 101 residents and 24 staff members had tested positive for the virus.

“There has not been anybody required to work when they have tested positive… we have found five instances where employees worked after they had been alerted that they are positive,” said IDVA Chief of Staff Tony Kolbeck.

Also Tuesday, the state’s health director said Illinois will receive far fewer doses of the COVID-19 vaccine than originally estimated. Dr. Ngozi Ezike told reporters that she expects the state to receive about 80,000 initial doses instead of the 400,000 doses that Illinois officials had anticipated, pending FDA approval of the vaccines.

She also said she still expects health care and emergency workers who could come into direct contact with coronavirus patients to be vaccinated first.

NewsNation affiliate WGN and The Associated Press contributed to this report.