LF amateur radio can be very dangerous as extremely high voltages and/or high currents can be generated with even quite modest powers because of the electrically short antennas. This is one reason why I stick to QRP(ish) powers on 136 and 500kHz.
See Mike's post:
This picture (linked from Mike's blog) shows the damage.It begs the question of how readily will an insurance company pay up when an amateur installation fails?
"I am currently off the air following my loading coil catching fire and damaging the house. I have had to take my mast down to allow access to the builders who are repairing the damage. Fortunately I was insured.
Damage to the G3XDV loading coil ....and roof! See http://g3xdv.blogspot.com
Hopefully I will be able to receive before Christmas and transmit again some time in January.
Details and pictures are on my blog at:http://g3xdv.blogspot.com