It may seem little weird at first but wait until we explain what exactly happened:
#1 The relay race (4×100) was happening normally when the error occurred.
#2 At the second exchange, the USA runner Allyson Felix, was to throw the baton to the third runner, English Gardner.
#3 But a Brazilian runner obstructed the way of Felix, because of which she lost control.
#4 Unfortunately, the next runner, Gardener, couldn’t understand this and hence a confusion occurred between both runners.
#5 Gardener soon stated running with a brilliant speed, but soon she realized that she had dropped the baton in the exchange zone itself during the confusion.
#6 Later, USA appealed for the review to Jury.
#7 Jury after reviewing disqualified Brazilian runners for obstructing USA’s runners.
#8 And the USA runners were given another chance in which they had to run without any opponents and surprisingly they set amazing record and entered in finals.