Fiscal 2022 is on track to become the deadliest year on record for migrants at the U.S.-Mexico border, according to a report by CNN.

Since Oct. 1 of last year, when fiscal 2022 started, Department of Homeland Security (DHS) officials have registered 748 migrant deaths at the border, according to the report.

That’s on track to surpass the number of deaths registered in fiscal 2021, when 557 migrant deaths were registered, setting a grim record.

The final figure for deaths in 2022 is certain to continue climbing in September, as high temperatures persist in much of the Southwest.

And the figures reported by DHS only take into account deaths confirmed by border officials, potentially undercounting hundreds of people who have perished in their attempts to enter the United States.

The rising lethality of border crossings is fueled by a variety of factors, including high temperatures, an uptick of migrant crossings in the traditionally quieter summer months and crossings in increasingly remote areas, in part to avoid border barriers.

Migration has also remained high for much of 2022, and more migrants are coming from beyond Mexico and Central America’s so-called Northern Triangle, Guatemala, Honduras and El Salvador.

The uptick in migrants from farther-away countries could also contribute to the crossing’s lethality.

DHS numbers have shown a steep rise in the number of migrants from places like Cuba, Venezuela and Haiti this year.

Often, those migrants are unfamiliar with the terrain along the U.S.-Mexico border, are more highly reliant on smugglers to find routes into the United States and have deteriorating health after long treks through Central America and Mexico.