They may not be quite as flaky as their banking counterparts, but news this week of Heller Ehrman’s dissolution is a reminder that US law firms can be surprisingly vulnerable institutions.

Heller’s closure follows a pattern familiar from other US collapses of the noughties; among them Brobeck Phleger & Harrison, Coudert Brothers, Altheimer & Gray and Testa Hurwitz & Thibeault. The end is often preceded by streams of partner departures, falling profits and – the real giveaway – failed attempts to attract white-knight merger partners.