1)
Which Kohanim fell via the sword?
1.
Rashi: Chofni and Pinchas [Radak - and other Kohanim who were with the Aron].
2)
Why did the widows not cry?
1.
Rashi: Also [Pinchas'] widow died when she heard - "va'Tishma... Nehefchu Aleha Tzireha" (Shmuel I, 4:19). The other widows died from heartache, like Pinchas' widow.