  Assuming the standard effective-field-theoretic formulation of Hawking
radiation, we show explicitly how a generic effective theory predicts a
firewall from an initially uneventful horizon for a spherically symmetric,
uncharged black hole in $D$ dimensions for $D \geq 4$. The firewall is created
via higher-derivative interactions within the scrambling time after the
collapsing matter enters the trapping horizon. This result manifests the
trans-Planckian problem of Hawking radiation and demonstrates the
incompatibility between Hawking radiation and the uneventful horizon.
