Philadelphia inspectors halted construction of the River Walk high-rise apartments, near John F. Kennedy Boulevard beside the Schuylkill, for nearly three weeks last month after discovering that work on the two-tower project was being done without proper permits.

Developer PMC Property Group was found in late May to be pouring concrete for elevator shafts up to the fifth floor of one of the 27-story buildings despite having a permit to complete only the building’s foundation, according to Department of Licenses and Inspections spokesperson Karen Guss.

Inspectors issued a stop-work order, but when they returned to the 60 N. 23rd St. project for a followup about two weeks later, they saw that construction had continued, so they shut down the site, Guss said.

If L&I examiners don’t have a chance to consider permit applications, they can’t be sure that developers’ plans conform to safety standards and don’t have a chance to set up checks during construction, Guss said in an email Friday.

“The permitting process is essential for public safety,” she said.

Work remained halted until June 26, when PMC was issued a “core-and-shell” permit at a cost of about $250,000, allowing it to build the inner structure and exterior walls, Guss said.

Other interior work, such as floors and partitions, will require additional permits, she said.

Guss said developers usually apply for all permits at one time, since obtaining them separately, as PMC is doing, obliges them to pay the same fees multiple times, driving up costs. They also can’t be sure that work they’re doing under existing permits will be easily compatible with steps they’ll have to take to comply with permitting requirements in later phases, she said.

“When smart developers build a big building like that, they get a building permit that covers everything,” Guss said.

A PMC representative declined to discuss issues related to the project’s construction.

The incident marks at least the second time in recent years that PMC has tussled with L&I.

In 2016, the department withheld permits for residents to occupy the developer’s then-newly completed One Water Street apartments near the Delaware River waterfront after it reneged on a commitment to include affordable units at the building in exchange for permission to build a taller project.

PMC later agreed to pay $3.75 million into Philadelphia’s Housing Trust Fund to pay for affordable units elsewhere in the city.