Back Hard to Place General Liability

I have an insured that is being nonrenwed for GL for her commercial rental properties due to a shock loss that is  slighlly over $500,000 in reserves for one loss.  A building she was renting out as a restaurant "blew up" due to a gas leak when the cook turned on the stove..Most likely the gas company fault.  

Having a tough time placing with my MGAs

Ay suggestions on markets that would help out?

Ramon M.