BARTLESVILLE, Oklahoma - Police are still investigating a medication mix-up that occurred at a group home in Bartlesville, which caused several people to be transported to a nearby hospital.

"It was a very chaotic scene,” said Bartlesville Police Sgt. Jim Warring.

Warring and others are trying to determine how ten people were given insulin instead of a flu vaccine at the Jacquelyn House, an intermediate care facility.

"Right now, we're just in the middle of the investigation to determine how this went wrong,” said Warring.

Warring said the investigation could take several days and there are multiple people they need to interview.

He said they first started getting calls yesterday evening, when each person who got the vaccine started to have bad reactions. At least 30 first responders rushed to the facility. Warring said at least half of those who were given a shot have already been released from the hospital, and to his knowledge everyone will be okay.

The State Department of Health said the facility now has 24 hours to provide an incident report to them that details what happened. They also said the pharmacist who administered the drugs was an independent contract pharmacist.

Police said he over 40 years of experience.

"He's been interviewed,” Warring said. “We're probably going to interview him again."

While they try to figure out how it happened, Warring said this could have been much worse if it wasn't for the quick response by first responders.

"They quickly identified what the problem was when they first arrived, and then they started administering care right there at the scene. That made all the difference in the world,” Warring said.

AbilityWorks of Oklahoma owns that facility. They sent a release saying in part that first responders "provided exceptional support to our residents and employees."