Coastal residents in the U.S. territory of Guam home to 172,000 military personnel on Wednesday were asked to seek shelter in re-inforced concrete structures made as preparedness for the impact immediately as Typhoon Mawar- strongest storm in decades threatened to hit the island in the Pacific region. Typhoon warnings remained in effect for Guam and Rota.

The typhoon weakened from Category 5 strength as it approached, but officials warned it remained extremely dangerous and was already bringing strong winds to the island as of 2 p.m. local time. The eye of the storm was about 45 miles east-southeast of Guam, the National Weather Service said, and the typhoon’s impact was expected to peak between 4 p.m. and 6 p.m.

“We are looking at the high potential for a direct hit and passage of a super typhoon on Guam,” the National Weather Service said in an update on Facebook. “This would be the first time in many years. This will be a benchmark storm that many folks on this island have not yet experienced.”

The US military sent away ships, President Joe Biden approved an emergency declaration and anyone not living in a concrete house was urged to seek safety.

The monster storm is expected to make landfall around Wednesday afternoon according to weather experts. Guam Gov. Lou Leon Guerrero ordered residents of coastal, low-lying and flood-prone areas of the territory of over 150,000 people to evacuate to higher elevations.

Guam is a crucial hub for U.S. forces in the Pacific, and the Department of Defense controls about a third of the island. Rear Adm. Benjamin Nicholson, Joint Region Marianas commander, authorized the evacuation of defense personnel, dependents and employees in areas expected to be affected.

Mawar could be the strongest storm to directly impact Guam since at least 1976, when Typhoon Pamela struck with sustained winds of 140 mph. If Mawar strikes with higher sustained winds, it would be the strongest since Super Typhoon Karen, widely regarded as the worst storm to ever hit the island, struck in 1962 with sustained winds of 172 mph.