Touch the World Through Prayer, W. Duewel, OMS, p. 85
In about 1949 a group of retired missionaries from China, with a few faithful praying friends, met for their regular missionary prayer meeting in Adelaide, South Australia. A great prayer burden and sense of urgency came on them as they gathered together. All felt especially burdened for Hayden Melsap, then assigned to the China Inland Mission. They unanimously decided to drop all preliminaries and go "straight to prayer." They prayed until they all felt a sense of peace and relief.
A few years later, when Hayden Melsap was on deputation in Australia, the missionaries asked him if he recalled any unusual occasion at that time. To their amazement, they found that on that day and hour Hayden and at least two other missionaries were backed against a wall in a courtyard in China, with communist guns leveled at them. Just as the officer was about to issue the command to fire, the door of the courtyard opened and a higher official entered. Shocked to see what was about to happen, he shouted, "Stop!" He then stepped up, put his arm around Melsap, and led him and the others to safety.
I heard this testimony from Hayden Melsap himself and also have it in writing from an Australian friend.