A consumer activist group released a report Tuesday outlining the collapse in communications that beset Puerto Rico after Hurricane Maria, and it urged the U.S. government to investigate the problems to avoid a repeat of the situation as the island prepares for another storm season.

The report by the group Free Press said the Federal Communications Commission should hold telecommunication companies responsible for the problems that emerged after the storm and also convene an independent commission to investigate the blackout similar to the one it formed after Hurricane Katrina ravaged New Orleans.

"There are still so many questions, and the FCC has failed to be transparent about the communications crisis in Puerto Rico and what carriers did or didn't do to help," said Carmen Scurato, senior policy counsel for Free Press.

The storm that hit on Sept. 20, 2017, caused a communications outage that prevented local and federal officials from learning about the extent of the damage and people's needs in the days and weeks that followed, with the storm knocking 96 percent of cellphone transmission sites out of service. One month later, 36 percent of sites were still not working, and in December 2017, the FCC noted that cable and landline phone services were "generally nonexistent."

The Free Press report includes 52 complaints filed by Puerto Rican customers after the hurricane that were obtained under the Freedom of Information Act. Complaints range from being charged for services never received to failed promises of waiving excessive data-usage fees.

Scurato said the group is still waiting for additional information requested, including how carriers responded to the complaints.

The FCC rejected the report and said it has worked to provide short- and long-term funding to restore and improve Puerto Rico's telecommunications system, including the creation of a $750 million fund announced last year.

"It's terribly misleading to claim that establishing a commission would be a more effective use of time and resources than the work we did and continue to do," the FCC said.

The report was released a day before the House Committee on Energy and Commerce holds an oversight hearing of the FCC, which issued a report earlier this month saying that communication outages in the Florida Panhandle after Hurricane Michael were lengthened by wireless carriers' poor preparation and coordination.