aphnō

(Translation from NRSV with a few modifications for a more literal meaning)

Acts

2: 2	And suddenly (aphnō) from heaven there came a sound like the rush of a violent wind, and it filled the entire house where they were sitting.
16: 26	Suddenly (aphnō) there was an earthquake, so violent that the foundations of the prison were shaken; and immediately all the doors were opened and everyone's chains were unfastened.
28: 6	They were expecting him to swell up or drop dead suddenly (aphnō), but after they had waited a long time and saw that nothing unusual had happened to him, they changed their minds and began to say that he was a god.