Answer: There was a violent earthquake, for an angel of
the Lord came down from heaven and, going to the tomb, rolled back
the stone and sat on it, (Matthew 28:2).
MORE INFORMATION AND/OR OTHER SCRIPTURE REFERENCES:
An interesting comment from The New International Bible
Commentary: "The rolling away of the stone was to
let the women into the grave, not to let Jesus out.
Resurrection life transcends grave-clothes, a sealed tomb and armed
men."