Amanda Bynes placed on mental lockdown after allegedly setting driveway fire

After a bizarre episode Monday night in which she allegedly started a fire in the driveway of an elderly woman in Thousand Oaks, Calif., troubled Amanda Bynes was involuntarily hospitalized on a psychiatric hold.

It’s the same 72-hour lockdown – called a 5150 hold – that a then-troubled Britney Spears underwent in 2008.

Sheriff’s deputies determined that Bynes, 27, needed to be hospitalized after they responded to the disturbance and questioned her. Here’s how it went down, according to TMZ.

The fire department responded to a home in Thousand Oaks around 9 p.m. Monday after someone noticed a small fire in the driveway.

Sheriff’s deputies were called when Amanda was allegedly found standing near the fire, reportedly holding a red gasoline can in her hand.

TMZ interviewed the woman who lives in the house, who said she had no idea what was going on until the cops knocked on her door.

They asked her: “Do you know anyone by the name of Amanda Bynes, or why she would have a vendetta against you?”

She answered no, then the cops described the young woman they found in the driveway, who they said burned part of her clothing in the incident.

After questioning Amanda, deputies decided she needed to be hospitalized for a 72-hour involuntary mental evaluation, which police, social workers and other mental health professionals can use if they believe a person is a danger to themselves or others.

Amanda was also accused of trespassing (while drunk) at a nearby retirement community after she was stopped by management at the facility and reportedly argued when they wouldn’t let her in, according to TMZ.

Stay tuned.