613 and 615 Fourth Avenue, at Fourth & 18th Street, were bought in September by Californian LLC South Slope Bliss. 613, a three-story frame building, was acquired for $2,500,000, and the larger, corner warehouse property, 615, for $7,300,000.
There are no current permits on file at either building, though 613 was set for demolition back in 2008. When I walked by today, it certainly looked like demolition was underway at 615, with the roof broken through, and the interior of the building full of rubble.
Any updates from nearby residents concerning this corner would be very welcome.