  This article deals with the first detection of gravitational waves by the
advanced Laser Interferometer Gravitational Wave Observatory (LIGO) detectors
on 14 September 2015, where the signal was generated by two stellar mass black
holes with masses 36 $ M_{\odot}$ and 29 $ M_{\odot}$ that merged to form a 62
$ M_{\odot}$ black hole, releasing 3 $M_{\odot}$ energy in gravitational waves,
almost 1.3 billion years ago. We begin by providing a brief overview of
gravitational waves, their sources and the gravitational wave detectors. We
then describe in detail the first detection of gravitational waves from a
binary black hole merger. We then comment on the electromagnetic follow up of
the detection event with various telescopes. Finally, we conclude with the
discussion on the tests of gravity and fundamental physics with the first
gravitational wave detection event.
