How do I cross examine the "insurance company" for the Triangle Shirtwaist Fire court case as defense lawyer?

I'm a defense lawyer for Blanck and Harris for a mock trial in my history class for the Triangle Shirtwaist Fire case.
The only details on the insurance company that I can find are that Blanck and Harris had a history of setting their buildings on fire to collect insurance money.
So how can I possibly cross examine the insurance company to win for Blanck and Harris' side??

Get creative. Learn all the facts of the case and read any deposition material or other statements they may have made. Then, at the mock trial, if they haven't prepared properly, you'll be able to pick them apart based on prior testimony.

That's what cross-examination really is. It's the opportunity to embarrass them and crush their credibility in front of the judge or jury.

So, learn the facts and learn all the prior testimony and statements (including ones to the Fire Dept's, Police, internal, etc.).

You'll also be able to ask them about other possibilities. "Did the police or your investigators look at anyone else?" "Couldn't x,y or z also have caused this fire" (since it's a mock trial you should be able to ask those- I don't imagine there will be any expert witnesses there).

It's not an easy process, but spend the time. You'll have fun!

I'd start with: why would the insurance company continue to insure them if the defendants allegedly had a history of setting fire to their buildings for the insurance money? No insurance company is going to provide fire insurance for people who are arsonists. So, either the insurance company is stupid or the defendants are just unlucky (and not malicious).