(CNN) "It can't be. Why would he do that?"

David Austin was shocked when he found out that his wife was one of 27 people who may have been given excessive -- possibly lethal -- doses of Fentanyl.The widower, who is suing an Ohio doctor that ordered the dose he believes killed his wife, was still distraught when he spoke to CNN affiliate WBNS

"27 people ..." he said in disbelief.

David's wife, Bonnie Austin, was brought in to Mount Carmel Health System in Columbus on September 30, 2018 with chest pains and difficulty breathing, according to a lawsuit David filed against the hospital, doctor, nurse, and pharmacist involved with her care.

Bonnie was diagnosed with a collapsed lung, stabilized, and moved to the intensive care unit, according to WBNS.

Then the osteopathic physician caring for her told Austin his wife was brain dead.

"I went berzerk. I had to take a walk," Austin told the station after he found out his wife of 30 years was brain dead. "I had to go. I just I had to go."

That day the physician ordered 600 micrograms of Fentanyl be given to Bonnie through IV, the complaint said. Within minutes, the complaint said, Bonnie died.

Medicine given 'without consent,' lawsuit says

Now, Austin is suing the doctor, nurse, pharmacist, and hospital involved with Bonnie's care for her death.

The complaint, filed on Tuesday, is the second this week alleging that the doctor gave a large dose of the pain medication, Fentanyl, to patients in critical care either negligently or with the intention of ending their lives.

The first lawsuit was filed Monday by the daughter of Janet Kavanaugh and alleges that 1,000 micrograms of Fentanyl were given to Kavanaugh with no therapeutic function and without her consent, according to the lawsuit.

Kavanaugh died on December 11, 2017.

Both David Austin and Kavanugh's daughter were alerted that in total, the doctor prescribed 27 patients "excessive doses" of Fentanyl.

Doctor fired

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CNN has sought comment from the doctor accused but was unable to secure a phone number.

Ed Lamb, Mount Carmel's president and CEO, released a statement acknowledging that the osteopathic physician ordered "more than what was needed to provide comfort" to patients whose families had requested that all life-saving measures be stopped.

The physician had worked for Mount Carmel for five years and has been fired, Lamb said. The incident has been reported to authorities.

It is unclear if any other patients may have died as a direct result of a lethal dose of Fentanyl.

"We're still gathering facts, and we're cooperating and sharing information with authorities, including the prosecutor," the hospital said in response to a question about additional deaths. "While that's happening, we won't be able to release all of the details of this tragedy."

The hospital said it has removed 20 members of its staff from patient care while the investigation continues, including nurses who administered the medication and pharmacists who were involved in patient care.

"On behalf of Mount Carmel and Trinity Health, our parent organization, we apologize for this tragedy, and we're truly sorry for the additional grief this may cause these families," Lamb's statement said. "Our team has contacted these families and will continue to answer their questions and concerns as best as we can."