A disturbing number of buildings across the U.S. could be at risk of facing the same fate as London's Grenfell Tower because of highly flammable exterior panels.

Fire-safety experts have determined the combustible-core panels used to cover a number of multistory buildings are a danger to anyone inside the structure because the panels, which are typically made of aluminum and sandwich a core made of polyethylene, a petroleum or natural gas-based plastic, are susceptible to catching fire, the Wall Street Journal reports.

These are the same panels being investigated in the U.K. for their role in the Grenfell Tower fire in London, which killed at least 80 people in June.

In terms of design, the panels allow for more flexibility. But when it comes to safety, experts have expressed concerns that tall buildings in particular are at risk, especially the upper floors, which are harder to evacuate quickly and are not reachable by fire-truck ladder. This is one of the reasons New York City has policies in place that prohibit combustible-core panels on buildings over 50 feet tall.

New York is the exception.

The International Code Council, a nonprofit advisory group based in Washington, D.C., that writes building codes in the U.S., for many years required metal-composite panels used for high-rise buildings pass a rigorous fire test. In 2009, a loosening of the fire-safety code was unanimously passed by the committee at the request of a panel manufacturer, the WSJ reports.

With a number of manufacturers selling fire-retardant panels for between 50 cents and $1 more per square foot in the U.S. compared with combustible-core panels, it means the question of cost savings versus ethics also comes into play, leaving much of the fate of the building and its residents in the hands of the developer.