Police in California who were summoned to perform a welfare check on former ER star Vanessa Marquez on Thursday shot and killed her after they say she threatened them with a realistic-looking BB gun.

The incident began unfolding just before noon when South Pasadena police officers responded to a home in the 1100 block of Fremont Avenue after getting a call about a 49-year-old woman suffering from seizures.

Sheriff’s Homicide Lt Joe Mendoza said the woman, later identified by sources and commenters on Twitter as Marquez, had eating disorders and appeared to be gravely disabled.

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Shot dead: Former Er actress Vanessa Marquez, 49, was shot and killed by police during a welfare check in South Pasadena Thursday

Police say they opened fire on Marquez after she pulled a realistic-looking BB gun on them during a wellfare check

A bouquet of flowers stands behind a broken window pane in Marquez's apartment on Friday

A workman is seen repairing bullet holes and a pipe in Marquez's now-empty unit

Three officers and a mental health care worker who was summoned to the scene spent 90 minutes trying to administer aid to her, during which time Marquez was allegedly 'extremely uncooperative.'

At around 2pm, police say the woman grabbed what looked like a semiautomatic handgun and pointed it at the officers, prompting them to open fire on her.

As The South Pasadenan first reported, the Stand and Deliver actress was struck at least once in the torso and taken to a hospital, where she died of her injuries.

Lt Mendoza said that the woman's gun that was seized from the house turned out to be a replica of a semiautomatic handgun.

Police say they had been to Marquez‘s home on many occasions in the past, reported KABC.

On Thursday morning, it was the woman's landlord who summoned them after becoming concerned for her well-being.

The Sheriff's Homicide Bureau has launched an investigation into the officer-involved shooting.

Marquez is best known for playing nurse Wendy Goldman on the popular NBC medical drama ER starring George Clooney between 1994 and 1997.

Last year, Marquez publicly accused the Oscar-winning actor and director of helping blacklist her after she spoke out about alleged harassment on the set of ER, including being subjected to racist and sexist remarks.

Clooney responded by insisting that he had no idea Marquez had been blacklisted and had played no part in it.

Paging nurse Wendy: arquez is best known for playing nurse Wendy Goldman on the popular NBC medical drama ER starring George Clooney between 1994 and 1997

Marquez made headlines in October 2017 when she accused Clooney of helping blacklist her after she spoke out about being harassed on the set of ER

Marquez, who was Mexican-American, claimed she was the target of racist and sexist remarks on the set of the medical drama

'I had nothing to do with casting,' the Ocean's 11 star said in a statement. 'I was an actor and only an actor. If she was told I was involved in any decision about her career then she was lied to. The fact that I couldn’t affect her career is only surpassed by the fact that I wouldn’t.'

After leaving ER, Marquez appeared in three episodes of the sitcom Malcolm in the Middle in 1999, followed by a few more roles in TV films and shorts.

Marquez had been vocal on social media about her struggles with various health problems, including what she described as terminal celiac disease, pulmonary embolism, osteoporosis and seizures.

She posted her final status update on Facebook on August 8, accusing Twitter CEO Jack Dorsey of hypocrisy for previously kicking her off Twitter for 'naming his friend George Clooney at the beginning of the #Metoo movement in October', but allowing the incendiary InfoWars host and notorious conspiracy theorist Alex Jones to remain on the platform.

Marquez was a long-time member of TCM Party - a group of cinephiles passionate about classic movies.

Other members of the group paid tribute to Marquez on Twitter Friday

'I am devastated to say that Vanessa Marquez @R2DivaLA was shot and killed by the South Pasadena police on Thursday afternoon,' @TCMParty tweeted. 'I met her through #TCMParty, I hope she knew how much we loved her and I hope too that she is at peace.'