LONDON — Hundreds of survivors and relatives of victims of the Grenfell Tower fire in London have sued makers of the flammable cladding and insulation that fed the blaze in an American court, trying despite steep legal obstacles to hold the firms liable as the two-year anniversary of the fire nears.

For a disaster that enraged Britons and set off sprawling investigations in London, the venue for the lawsuit — the Philadelphia County Court of Common Pleas — was unorthodox.

But it reflected an increasingly prevalent dilemma for lawyers bringing cases against multinational corporations. Drawn to American courts for plaintiff-friendly liability laws and the opportunity for big payouts, the lawyers and their clients must nevertheless contend with questions about when American rules should apply in disasters abroad.

[Britain vowed big changes after the Grenfell Tower burned. Thousands remain stuck in firetraps.]

The Grenfell lawsuit, launched in Pennsylvania because the cladding maker, Arconic, has its headquarters there, has also stirred concern in some quarters about a clash between Britain’s slow and painstaking inquiries into the fire and simultaneous American litigation.