Preetinder Kaur Negi, 26, a graphic designer and small-time model from Andheri, was killed in a bizarre accident yesterday evening when a glass window pane fell from the 26th floor of the Oberoi Hotel here, slicing her head and killing her instantly.The accident happened at 6.15 pm when the window pane came crashing down on Negi as she was walking towards the hotel’s swimming pool on the 4th floor. Negi’s family said she often went to the Oberoi for a swim and was a regular at the hotel’s restaurants. But a hotel spokesperson claimed only hotel residents are allowed to use the pool. ‘‘Preetinder was talking on her mobile to her father when the accident occurred,’’ said Santoksingh Ahuja, Negi’s brother-in-law. ‘‘It was her father’s birthday and she was wishing him over the phone.’’Priya da Cunha, the Oberoi’s PR executive, said it was ‘‘a very tragic accident’’. ‘‘It involved a non-resident guest and we informed police immediately. It seems a strong wind shook the window pane.’’