The FTs Alphaville blog draws our attention to bad news on the wires this morning, as the Dow closes below 8,000 and the FTSE trades below 4,000, we get the news that Granite Master Issue PLC, the trust that is 28% of the UK mortgage securitisation market, is reporting a “non-asset trigger event”. It is telling lenders that Northern Rock‘s collaterallisation, and hence credit worthiness, has declined significantly.Granite is the single biggest funder of the UK mortgage market. If it goes tits up, £38 billion of Northern Rock mortgage assets could be liquidated…