Editor's note: This updates with recovery work at Caribbean National Park System units halted in advance of Hurricane Maria.

With Hurricane Maria bearing down Monday on the Caribbean with the promise of heavy rains and high winds, recovery efforts at Virgin Islands National Park and other units of the National Park System in the Caribbean impacted by Hurricane Irma were halted.

"Assessments and recovery efforts in national parks in the Caribbean have been put on hold until Hurricane Maria passes," a Park Service release said Monday afternoon. "Currently, 305 NPS employees from outside the affected parks are assisting, representing 88 parks in 35 states. The safety and support of all NPS employees working in the parks is the priority for the NPS response. As cleanup from Hurricane Irma continues, preparations are underway to relocate NPS employees and their families from St. John to Puerto Rico as Hurricane Maria approaches the U.S. Virgin Islands."

Hurricane Maria was expected to sweep reach the Leeward Islands late Tuesday or Wednesday with heavy rains and winds above 110 mph, and could hit the U.S. Virgin Islands on Wednesday.

"Maria is expected to produce total rain accumulations of 6 to 12 inches with isolated maximum amounts of 20 inches across the central and southern Leeward Islands, and the U.S. and British Virgin Islands through Wednesday night," the National Hurricane Center said Monday afternoon. "Rainfall amounts of 6 to 12
inches with isolated maximum amounts of 25 inches are expected across Puerto Rico."

At Accuweather, forecasters said that while Maria isn't expected to reach the intensity of Irma, a Class 5 hurricane, it nonetheless will be the third tropical system to impact the area in two weeks.

"St. Croix, Culebra, Vieques and Puerto Rico may also take a direct hit and end up with more substantial damage when compared to Irma," said AccuWeather Senior Meteorologist Alex Sosnowski. "With Irma stripping much of the vegetation in the northern Leeward and Virgin Islands, there is a much greater risk of flash flooding and mudslides even if the eye wall of Maria passes by to the south."

At Virgin Islands National Park on the island of St. John, the devastation from Irma was hard to fathom.

"Virgin Islands National Park took a thrashing," Joe Kessler, president of Friends of Virgin Islands National Park, wrote in an email. "The forest is unrecognizable. Most trees have been topped, fallen over, and/or suffered significant limb breakage. Many VINP staff houses suffered severe damage and some have been destroyed. The Archeology Lab, housed in the oldest masonry structure on St. John, has been destroyed (collections had been removed in anticipation of the storm). Maho Bay Road has been washed out. And, all trails are impassable due to fallen trees and branches."