ST. PETERSBURG — The Pier is one step closer to becoming a memory.The city has applied for a joint permit with the Southwest Florida Water Management District and the U.S. Army Corps of Engineers to demolish the iconic inverted pyramid built in 1973.No other state or federal permits are needed. Approval of the permit, which cost $4,450, could take six to 12 months, said Mike Connors, the city's public works administrator. On Thursday, city officials unsealed proposals from firms seeking the $4.5 million contract for the demolition work. He expects final tabulations of the bids to be done next week.The City Council will have to approve the demolition work and the construction contract for the new Lens, expected to cost $50 million.The Pier is scheduled to close to the public May 31. Retailers will be given 60 days to remove equipment and supplies. Demolition is estimated to start in September 2013.