The wave of mud flooded streets in Kolontár, where four people were confirmed dead, and Devecser, where the flow was powerful enough to move cars and vans. The cause of death of the Kolontár victims has not been formally confirmed; a spokesman for the National Directorate General for Disaster Management (NDGDM, Országos Katasztrófavédelmi Főigazgatóság) said that they had probably drowned. A further six people were still missing 24 hours after the accident.

The NDGDM said that the high pH mud was considered hazardous and would cause an alkaline reaction on contact if not washed off with clean water. The mayor of Devecser said that 80–90 people had been taken to hospital with chemical burns. Péter Jakabos, a doctor in the hospital in Győr where many of the injured had been taken, said on Magyar Televízió that it might take days for the full extent of any burns to be realised. Magyar Alumínium (MAL) said that mud was not considered containing toxic elements according to EU standards. Initial measurements by the NDGDM showed the sludge to be extremely basic, with a pHvalue of 13.

The chemicals extinguished all life in the Marcal river, and reached the Danube River on 7 October, prompting countries located further down the river to develop emergency plans in response.

On 11 October, the Hungarian government announced that the managing director of MAL had been arrested, to be charged with "criminal negligence leading to a public catastrophe." Also on the 11th, the government took control of MAL, appointing a commissioner to manage the company. The government planned to focus on compensation for the incident, job security, and identifying further locations at risk of accidents.