Sedov-Taylor-Rayleigh blast equation, though this video isn't high enough frame rate to more than ballpark it I think. Tower is ~180m high, so 0.2 sec would be a bit over 1 kiloton instead? But definitely not remotely 13 kt. Still serious of course, when SpaceX suffered launch complex damage during some of its incidents it took a solid 6-12 months to fix.

Everyone can be glad though that no hypergolics are involved at least!

The estimate is roughly E = rho*R^5/t^2 with rho the density of air: https://en.wikipedia.org/wiki/Taylor%E2%80%93von_Neumann%E2%...