CBS News reported Monday new details that have emerged in the tragic disappearance of two U.S. soldiers during “African Lion” in Morocco.

African Lion is the largest joint military exercise conducted yearly by the U.S. Africa Command (AFRICOM), involving African nations and NATO allies training for warfare on land, air, sea and even cyberspace. More than 7,000 soldiers from more than 30 countries are stationed at a base in Morocco for African Lion.

The missing soldiers had gone on a hike to watch the sunset when one of them fell into the water. Knowing he couldn’t swim, the second soldier jumped in to help just as a huge wave pulled him under. A third service member leaped in to rescue the other two but failed after struggling with the waves. The third soldier made it back to shore unharmed. The soldiers were last seen at the cliffs by the ocean near the Cap Draa Training Area.

The U.S., Morocco and others sent drones, vessels, divers and aircraft to search for the missing soldiers.

A Boeing P-8 Poseidon maritime patrol and reconnaissance aircraft arriving from Naval Air Station Sigonella in Italy to Morocco Tuesday afternoon will aid in the rescue efforts. Meanwhile, Morocco is sending scuba divers to search the caves that are a characteristic geographic feature of the North African coast.