On June 27, 1929, Brockwell and a friend, Los Angeles' advertising man Thomas Brennan, were involved in an automobile accident near Calabasas, California. She was crushed beneath the automobile driven by Brennan. The auto went over a 75-foot (23 m) embankment on the Ventura Highway near Calabasas. Seriously injured, four blood transfusions were performed in an effort to save her life, the last just before her death. Brennan recovered after sustaining serious injuries. He said a bit of dust had blown into his eye, temporarily blinding him. Following a second blood transfusion, Brockwell appeared to improve until peritonitis set in from her internal injuries, particularly a puncture of her large intestine. After two more transfusions, Brockwell died on July 2, 1929 at 7 p.m. at Osteopathic Hospital. No negligence was placed on Brennan, who was still recovering in the hospital.