Big Bangs were explosions which "caused everything to come into being". River Song helped cause "a few of those in [her] time". (PROSE: The Guide to the Dark Times)
Event One of N-Space was a Big Bang, commonly known to that universe's inhabitants as the Big Bang. (TV: Terminus) It took place at 11:00 a.m. on 15 February in the year 13,500,017,903 BC. (PROSE: Time Traveller's Diary) After the universe was nearly destroyed by the Doctor's TARDIS's exploding at every moment of Time and Space, causing total event collapse, the Eleventh Doctor flew the Pandorica into the heart of the explosion to create Big Bang Two, which restored the universe. (TV: The Big Bang)