What happened to my fluorescent light bulb? Are these fumes toxic?

Your question re toxic fumes is justified, but as another respondent has said there's zip to fret about unless the actual CFL (Compact Fluorescent lamp) gl is fractured or breaks when you remove it from the light socket. There are approximately 20 electronic components in the base of these complex lights and what I've noted when some of them burn out, usually well before the stated 6000- 8000 hours of the expected life of these things. the Electrolytic Capacitor (6 +mF at 400v - 500volts) usually blows it "top" as it becomes pressurised over time before it pops it's expandable cap as a safety measure. The act of the capacitor detonating can be the the reason why you heard a "pop" and in some cases I've investigated why , a 2.2 ohm X 1/2 watt resistor will also open circuit with a pssst. and also with a section of the printed circuit (copper strip) dis integrating off the PC cct. board either Fiber Gl or similar material. As said these type of lamps are supposed to be more economical to run but the saving in power usage is out weighed by the carbon emission and by the cost of having to buy more than other earlier Fluorescent type tubes or incandescent globes etc. You also have to appreciate that trillions of these CFLs are manufactured in Asian countries for world usage and any amount of "green house Co2) gases from their creation just escapes into the atmosphere in huge amounts.