After Fire, Amanda Bynes on Mental Health Hold

All right. Stay tuned. Turning now to amanda bynes. Ordered to psych ya the resting after starting a fire in a neighbor's driveway. Abbie boudreau with more on what amanda bynes is doing. What's on fire? It's a small piece of cloth. And it a gasoline tank. Reporter: The former child star, witnesses say, set fire to this driveway on monday night. I saw this girl laying down with her left pant leg on fire. When I look at her, amanda bynes. She was, like, really frantic. Like, she wanted to get out of there. And she's like, my dog has been burned. Reporter: He says bynes tried hailing a cab to get away. I was like, don't take her. I don't know what's going on with her at all. Do not let her in the car. Reporter: Deputies responded to the scene and talked to bynes. But did not charge her with a crime. It determined that she met the criteria of 5150. That's a psychiatric hold. The patients can be taken involuntarily from where they are and put in a setting where they are evaluated by special specialists in a hospital. Psychiatrists and a multidisciplinary team will evaluate her. Reporter: Bynes was on a mental health hold where she can be observed up to 72 hours. The "hairspray" actress has been in and out of court. Sparking hair-raising headlines with her colorful wigs and bizarre behavior. I think amanda has been in the public so long, that there's a twisted part of her that thinks this attention is good. Reporter: Even taking to twitter. Calling miley cyrus ugly and jenny McCarthy an old lady. This could be a catalyst for significant change in her life. Reporter: For "good morning america," abbie boudreau, abc news, los angeles.