Looking at West Bengal Chief Minister Mamata Banerjee at the launch of free WiFi in Kolkata's Park Street last evening, you wouldn't think so. But yesterday was black Thursday for her party. First, its MP Srinjoy Bose, quit the Rajya Sabha and the Trinamool. Significantly, Mr Bose had got bail on Wednesday, 75 days after being arrested in the Saradha scam. Trinamool responded by saying Mr Bose was under pressure from the power at the Centre.