officers ambusheand kille. twseparate tacks in wa ernight >>> breaking news right now. officers am bashed and killed. two separate attacks in iowa overnight. we're live with the details just coming into our newsroom. >> reporter: pete suratos in san francisco where the city could be naming its new police chief shortly. sources tell us there's a familiar name on that list. i'll tell you who coming up. >>> a scare on b.a.r.t. the investigation now under way to find out what caused an electrical explosion on the tracks overnight. "today in the bay" starts right now. >>> a very good morning to you. now wednesday, halfway through your workweek. thanks for joining us, i'm laura garcia-cannon. >> i'm sam brock. we had a scare earlier this week, of course we had halloween. the scary thing this morning is the fact the temperatures have dipped. >> one of our burr months, november. low to mid 40s around the north bay valley. chilly, clear skies, a little patchy fog which mike is tracking. in the north bay, around fairfax, 45 degrees. oakland 50 this morning, right near the water's