Work began this week on what will eventually be the ice rink at Little Caesars Arena.

That's the highlight of the current phase of construction of the $635 million building that will be home to the Detroit Red Wings and Detroit Pistons when it opens in September.

Detroit-based RBV Contracting is doing the ice rink work. The playing surface will sit about 40 feet below street level, and the basketball court will be erected over the ice while the teams share the venue during the concurrent seasons.

Temperatures are cold and snow flurries swirl around the arena site, but much of the arena bowl has been enclosed and temporary heaters are being used to keep the building above freezing, Olympia Development of Michigan said in a statement. Olympia is overseeing the arena project on behalf of Wings owner Mike and Marian Ilitch.

Work remains on schedule, Olympia said.

The arena's 7,666-piece structural steel frame is finished, Olympia said, and ongoing work includes masonry, mechanical and drywall. Brick masonry is nearly complete on the north side of the arena. More than 86,000 cubic yards of concrete have been poured for the arena and adjacent buildings.

Sometime during the first quarter, work will begin to install the high-strength transparent plastic membrane (known in technical terms as ethylene tetrafluoroethylene) that will create the ceiling of the unique covered concourse that's being called the Via. It will be both a traditional concourse and a large street-style shopping and dining area and will connect the arena bowl and the detached buildings that front Woodward Avenue and Henry Street.

Work also is underway on installing the "jewel skin" decorative exterior surface that wraps arena bowl. Images can be projected onto the jewel skin, Olympia said.

Additionally, foundation concrete and structural steel are complete for two new retail and office buildings near the arena on Woodward Avenue and on Henry Street, Olympia said, and foundation work continues on the new mixed-use building southwest of Henry and Park streets.

More than 1,000 workers are on-site in three shifts six days a week, Olympia said, including more than 140 apprentices so far.

Crain's requested an update on the project's struggle to meet workforce goals, but Olympia said it didn't have updated data from the city.

Before construction began in September 2014, Olympia inked an agreement with city officials, in exchange for $250 million in tax-exempt bonds and other incentives, to maintain an arena project employment base consisting of 51 percent residents of Detroit. The contractors have failed to meet that goal, largely because the city lacks enough skilled workers, and have paid about $500,000 in fines that pay for skilled trades training for city residents. The workforce level is monitored monthly.

A message seeking the latest hiring information was left for Detroit's office of human rights, which monitors and enforces the hiring requirement for the project.

The arena is the centerpiece of a 50-block revitalization, with construction of new offices, retail, restaurants and bars, residential, and green and public spaces. Known as The District Detroit, it's estimated to cost $2.2 billion, some of which is being paid by Olympia and some of which will come from outside investors.

Ninety percent of the $575 million in arena construction contracts awarded so far have gone to Michigan companies, and $345 million of that has been to Detroit-based businesses, Olympia said.

Olympia recently installed a webcam that broadcasts live inside the arena at districtdetroit.com/live-web-cam.

In other work in the district, the first structural steel has been erected for the $150 million Ilitch-owned Little Caesars pizza chain headquarters along Woodward Avenue. That project, a nine story, 234,000-square-foot office building, is scheduled to be done in 2018.

The last piece of structural precast concrete has been placed at the new Tiger Garage No. 2 on East Montcalm St., and it's on schedule to be ready for Opening Day in April.