Heche, 53, was inside a blue Mini Cooper when it hit a home in Los Angeles on Friday. Her representative told PEOPLE on Monday that the actress is in "critical condition" at the hospital.
"She has a significant pulmonary injury requiring mechanical ventilation and burns that require surgical intervention," according to the statement. "She is in a coma and has not regained consciousness since shortly after the accident."
More details about the Emmy winner's whereabouts before the crash are also being reported. Richard Glass, owner of Glass Hair Design in Venice, told The Los Angeles Times that Heche was at his salon, roughly two miles from the crash site, that morning and "wasn't speaking in cursive" at the time. (He said he uses the phrase "speaking in cursive" to describe someone who seems intoxicated.)
The Los Angeles Police Department is also investigating the crash, and authorities have a search warrant to test her blood to determine if Heche was intoxicated during the incident, according to The Times.
Axelle/Bauer-Griffin/FilmMagic Anne Heche
In the salon, Glass said Heche asked him about a bright blue wig. When he told her it was unavailable, he said she would buy a red one.
While Glass said he didn't recognize the Six Days Seven Nights star at first, he realized who she was as he rang her up. He then snapped selfies with Heche that he posted on Instagram.
He told The Times that Heche, who he said acted like "a sweet little girl," was "very pleasant," calling their meeting "very, very random" and "so strange."
Glass added that, during their interaction, Heche "grabbed my face" and wondered if he had done her hair before. He said he hadn't but offered to work with her.
"Lynne called me and asked me if I was sitting down, and then told me a car had crashed through the home and it was on fire," recalled Jennifer Durand, who has owned the house for 24 years. "She could barely speak so it took a few minutes to really understand what was happening."
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"When I arrived, we hugged and cried a lot. In that moment, I was just so relieved and grateful that she and her animals had survived this," Durand continued. "Nothing could have prepared me for what the house looked like."
Noting that the residence was her "first," Durand said of her current tenant, "Lynne has made it her home … there are a lot of memories there, and it is just gone."
Praising first responders, Durant told PEOPLE, "The firefighters helped us sift through it — I can't accurately describe how that feels. Every firefighter and officer that I spoke with were incredibly kind and helped in every way they could. They spent so much time with us, explaining everything and helping search for things. I am especially grateful for their response."