The Department of Housing and Urban Development announced Monday that it would provide $5 million to install carbon monoxide detectors in public housing, after an NBC News investigation revealed the lack of protections for millions of low-income tenants who live in federally subsidized rental units.

The funding for public housing authorities represents "the first time HUD is targeting grants specifically for the purchase and installation of carbon monoxide detectors,” the department said in a press release.

Carbon monoxide detectors are not currently required in HUD housing, despite the deaths of at least 13 residents from carbon monoxide poisoning since 2003, according to an NBC News tally based on federal records, interviews with local housing officials and local news reports. HUD does not keep an official tally of carbon monoxide deaths in the housing that it oversees.

“Carbon monoxide poisoning presents a risk to families living in public housing,” HUD Secretary Ben Carson said in the press release Monday. “This funding will allow more public housing authorities to purchase and install these lifesaving detectors.”

Tim Kaiser, executive director of the Public Housing Authorities Directors Association, praised the agency for making the funds available. “This funding is necessary because public housing authorities, especially smaller agencies, have been deeply affected by more than a decade of profound disinvestment in the Public Housing Capital Fund,” he said. “PHADA hopes that HUD will continue to provide this vital funding on an ongoing basis.”

HUD announced last month that it would issue a new rule to make carbon monoxide detectors mandatory. But the agency has not unveiled a formal proposal yet, raising fears among housing advocates that more residents in HUD housing could die before landlords are required to install the detectors.

Housing advocates, along with Sen. Bob Menendez, D-N.J., urged HUD last week to take immediate executive action to require detectors, warning that delays could mean more lives lost. But HUD said it would need Congress to pass a new law in order to move faster. The agency is currently helping Menendez and Sen. Tim Scott, R-S.C., to draft a bill.

A separate bill, introduced in March, would require carbon monoxide detectors in federally assisted housing and would provide $10 million in funding. The bill has yet to advance in either the Senate or the House.

Sen. Kamala Harris, D-Calif., who introduced that bill, said she was encouraged by HUD’s announcement of funding Monday but stressed that Congress still needs to act to protect families from carbon monoxide poisoning.

“Every parent deserves a safe home for them and their children, which is why I’m calling on my colleagues to codify this requirement into law and provide even more funding for public housing units to install these lifesaving devices,” Harris, who is running for president, said in a statement.

The $5 million in HUD funding, drawn from the agency’s emergency safety and security program, is restricted to local housing authorities, which oversee about 1.2 million public housing units across the country, the agency told NBC News. The funding is not available to private landlords who own and operate housing for more than 3.4 million households who receive rental assistance from HUD.

“While we welcome $5 million for the purchase and installation of carbon monoxide detectors, the funding leaves many public housing units unprotected," Menendez said in a statement. "All public housing units need carbon monoxide detectors, not just some of them."