Pia Zadora SWAT Team Swarmed After She Allegedly Chokes Son

6/3/2013 9:52 AM PDT

Pia Zadora -- SWAT Team Swarmed After She Allegedly Choked Son


We now know why former Broadway star Pia Zadora was arrested in Vegas over the weekend ... she allegedly tried to choke out her son ... TMZ has learned.

Zadora -- who famously appeared in the Academy Award disaster scene in "Naked Gun 33⅓"  -- got into an argument Friday night with her 16-year-old son Jordan because he refused to go to bed at a timely hour.

Jordan told police he wanted to stay outside and talk to his stepbrother, so Zadora sprayed them with a hose to force them inside.

Jordan told cops his stepbrother tried to calm Pia down and she attacked him, punching him and scratching his face. 

An hour or 2 passed, and -- according to the police report -- Jordan tried calling 911.  He claims Pia tried to take his phone away, choking him in the process.

When cops arrived, they say everyone in the house -- Pia, her son and stepson, as well as her husband -- refused to come out to speak to them ... so SWAT formed a perimeter around the house.

Pia and her son Jordan eventually came out and spoke to police, and, according to the police report, Pia admitted she may have injured/scratched Jordan and her stepson during the scuffle ... but only by accident.