B757 Undifferentiated or Other Model
Ground Event / Encounter Other / Unknown; Ground Incursion Runway
General None Reported / Taken
Equipment / Tooling
I was sitting [at the gate] when I began to hear a horn blowing like crazy then I saw a tractor trailer come to a complete stop and the horn was still being blown; then a [company] pickup truck comes into view and starts blowing their horn again; then I noticed a string of foreman carts sitting out in the middle of the runway. I retrieved the carts suspecting the brakes on the first cart wasn't working because the tongue was in the up position. Upon further investigation the brakes on the first cart wasn't working. The cart was tagged and removed from service and parked at our [ground service building]. A 757 aircraft passed the area just prior to the movement of the carts which move with surprising speed and a collision would have been unavoidable for that aircraft. Btw the [company] truck nearly collided with the string of carts as they began to move. It was dark; rainy; and windy.
Ramp employee reported a string of baggage carts rolled onto the runway when the brakes failed on the lead cart.