A few in-game days following the events, a small group of bandits will occupy the ruins of the town (the lock on either gate must be picked, or one of the bandits can open it). The named residents of Helgen, besides Haming, are not seen again after the escape, and it can be assumed that they had either perished during the attack or managed to flee to safety.
The Dragonborn was among the survivors to escape in the resulting chaos. However, moments before the sentence was carried out, Helgen was attacked and destroyed by Alduin. Though the Dragonborn's name was not on the Empire's list of those to be executed, the Imperial Captain overseeing the executions ordered their death regardless. Also among the prisoners was a horse thief of Rorikstead, Lokir, and an individual later revealed to be the Dragonborn, who had also gotten caught up in the Imperial ambush, apparently while attempting to cross the border from Cyrodiil. On the 17th of Last Seed, 4E 201, Ulfric Stormcloak and a bodyguard of Stormcloak Soldiers (including Ralof and Gunjar) were sent to Helgen for public execution after being caught in a trap set by the Empire near Darkwater Crossing. Before its destruction by Alduin, the keep was controlled by the Imperial Legion.
Helgen was a thriving town and keep on the southern border of Skyrim with Cyrodiil.