Acts 16:26

26 Suddenly 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.

Acts 16:26 In-Context

24 Following these instructions, he put them in the innermost cell and fastened their feet in the stocks.
25 About midnight Paul and Silas were praying and singing hymns to God, and the prisoners were listening to them.
26 Suddenly 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.
27 When the jailer woke up and saw the prison doors wide open, he drew his sword and was about to kill himself, since he supposed that the prisoners had escaped.
28 But Paul shouted in a loud voice, "Do not harm yourself, for we are all here."
New Revised Standard Version Bible, copyright 1989, Division of Christian Education of the National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved.