LUCKNOW, March 21 -- Two members of a family died while another is battling for his life in a suspected case of poisoning in Banthra area here on Friday. Though preliminary police probe points to suicide, the exact reason remains unclear. The incident occurred in Neewa village, where a 52-year-old woman and her 30-year-old son were declared dead at a private hospital. The 55-year-old head of the family is undergoing treatment and is in critical condition. As per reports, the case came to light around 4 am when the younger son woke up to find his father vomiting. He then found his mother and elder brother lying unresponsive in a room, with froth around their mouths. He alerted relatives, following which all three were taken to a nearby hospital. Doctors declared the woman and her elder son dead. Police said a suicide note was recovered from the deceased son's pocket. "We alone are responsible for our deaths," the note read, indicating a possible suicide pact. The family ran a tea and snacks stall along with a paan kiosk on the outskirts of the village. The younger son told police there was nothing unusual on Thursday. He said he had prepared dinner, but his parents and brother told him they had already eaten outside before going to sleep. Police found a torn five-page notice pasted outside the house. A portion carried the words "Security Officer" along with a Mumbai address. Officials said the document is being examined. Family members and neighbours said two unidentified persons had been visiting the house regularly. Villagers also claimed that some loan recovery agents had come to the house around 10-12 days ago after repeated phone calls allegedly went unanswered....