Six fire engines and around 35 firefighters have been called to tackle a well-developed fire that has ripped through a basement of a Croydon tower block.   Crews were scrambled just after 11pm on Sunday evening to the tower block complex on Addiscombe Road in the town.     The blaze is understood to have broken out within the basement of  No. 1 Croydon (formerly the NLA Tower, and colloquially the 50p Building, the Wedding cake  at 12–16 Addiscombe Road, next to East Croydon station. It was designed by Richard Seifert & Partners and completed in 1970. It has 24 storeys and is 269 feet (82 m) high No. 1 Croydon is occupied by a number of companies and organisations, including Atkins, Directline holidays, HotGen, dotdigital, Natterbox and Global Resourcing.   The incident is currently ongoing A number of road closures have also been put in place to assist with tackling the blaze. The cause of the fires not currently known but is understood to be under investigation The LFB has been approached for comment   More to follow