MOHALI: A 25-year-old woman allegedly committed suicide by setting herself on fire in Lalru on Thursday. Her family members were not home at the time. Doctors at GMCH declared her dead.Police said they are yet to ascertain what drove her to the extreme step. While her family members said they did not know why she killed herself, police are not convinced with the reply.Lalru SHO said they have recorded the statement of her family members and have initiated proceedings under section 174 of the CrPC . No suicide note was recovered from the spot..