'ER' actress Vanessa Marquez killed by police after she pulled a BB gun on officers

"ER" actress Vanessa Marquez was shot and killed by police Thursday after she pulled a BB gun on officers, Lt. Joe Mendoza of the South Pasadena Police Department confirmed to USA TODAY Friday.

Officers thought the weapon was a semi-automatic handgun.

The incident occurred during a welfare check to the 49-year-old's apartment in South Pasadena, California.

When officers arrived around noon Thursday, they "noticed the female was having seizures" according to a press release received by USA TODAY Friday. Paramedics were called to assist.

"While speaking to her, officers became aware she was possibly suffering from mental health issues, became uncooperative, and appeared to be unable to care for herself," the statement continued. "They continued to speak to her for over an hour and a half in an attempt to offer her medical care. She then armed herself with a handgun and pointed it at the officers, at which time an officer-involved shooting occurred."

Marquez was then transported to a hospital where she was pronounced dead.

No officers were injured during the incident.

Marquez played Nurse Wendy Goldman in the first few seasons of the NBC hit medical drama series. She also starred in the 1988 teacher drama "Stand and Deliver."

Her "Stand and Deliver" costar Lou Diamond Phillips wrote on Twitter that he was "sick to learn of the tragic passing of my friend."

"I was not aware of the pain she endured due to her conditions and saddened to think that they may have contributed to her untimely demise," Phillips wrote. "Her light and her soul still shine in the performances she gave us."