Ten minutes passed before his heart slowed down and he was able to steel his courage enough to swim the final leg.
Tonelli swam the second leg in a time of 1 m 55.94 s.
Berens swam the third leg in a relay split time of 1:46.29.
Michael Phelps, swimming the final leg, won a record 19th Olympic medal.
He swam the first leg in the final to help Australia win the bronze medal.
He retained his position for the final, where he again swam the third leg.
She swam the third leg in the final, but could only manage 1 min 59.28 s as Australia came fourth.
In the 4 x 100 m freestyle relay, Lauterstein swam the third leg.
He swam the second leg of the final in the 4x100 freestyle relay, winning a bronze medal.
She swam the third leg of the final in 1:56.70.