I note that at Crewe, the 09:56, 10:22, 10:29 and 10:56 to London were all cancelled. The 09:56 (from Chester) and 10:56 (from Holyhead) 5-car Voyagers were terminated at Crewe, with the 10:22 (from Liverpool) and 10:29 (from Manchester) Pendolinos cancelled throughout.
The 09:56 is the first off-peak service (scheduled to arrive into Euston at 11:39) and very popular. The platforms at Crewe are busy enough when passengers are waiting for the 09:56 and 10:22/10:29. It must have been complete chaos with all these passengers, plus the passengers decamped from the 09:56 and 10:56, waiting for the 11:22 to Euston, which didn't depart until 11:55 and isn't expected to arrive into Euston until 14:00.
I wonder if passengers were allowed on the (peak) 09:30 departure to London, which is a quiet non-stop 11-car Pendolino from Manchester. It arrived into Euston today at 12:25, which is considerably later than the usual arrival time of the off-peak 09:56 departure.
According to realtimetrains, it looks as if it would have been quickest to direct passengers to the 10:01 via Birmingham, which departed Crewe at 10:14 and arrived into Euston at 13:15.
Irrespective of the disruption caused, however, I am very glad that no one was seriously injured by what could have been a substantially worse incident.