DETROIT — Four developments totaling more $2 billion in new investment are planned for downtown Detroit.

The projects could bring 15,000 construction jobs and up to 9,000 permanent jobs, plus make the city more attractive to expanding companies such as online retail giant Amazon.

High-rise buildings are part of the developments, which would be the latest updates to a downtown that just over a decade ago struggled to attract businesses and people.

“Detroit is going vertical,” Bedrock founder and chair Dan Gilbert said. “In fact, that is the only way to create any type of significant expansion in the city because we are virtually at full occupancy for residential and commercial space in both downtown and Midtown.”

The largest investment would be the $900 million redevelopment of the former J.L. Hudson Co. department store site. The project includes a building with a sky deck above residential floors. It also would feature dining, retail, office and public space.

A 35-story office tower would be part of the $830 million Monroe Blocks project between the Greektown entertainment district and Campus Martius Park in the heart of downtown. Like the Hudson’s project, Monroe Blocks would have residential units, dining and retail.

Bedrock also plans to spend $313 million to rehab the historic Book Building and tower into apartments, retail, offices and a hotel.

A $95 million expansion of One Campus Martius will include office space to help attract new firms and jobs to the building, according to Bedrock.

“The economic impact this project will have on our city is larger than anything we’ve seen in generations,” said Detroit Mayor Mike Duggan. “Not only will it produce thousands of new jobs and opportunities for Detroiters, it will reshape the city’s skyline and attract even more re-investment in Detroit.”

Construction on the four developments would take place over five years. Bedrock says it will finance most of the projected costs.

“These critical projects will attract new visitors and residents as well as countless new visitors and businesses like Amazon to the city, which will create a ripple effect of economic impact and job creation,” Gilbert said Wednesday while announcing development plans.

Communities across the U.S. have been putting together sales pitches to woo Seattle-based Amazon, which is looking for a site for its second headquarters. The prospective $5 billion investment could bring with it 50,000 new jobs.