Magnussen and Hamilton to start from pitlane Sunday
The McLaren driver looked set for a decent position on the grid, but it started to rain during the final qualifying session and he failed to react quickly enough in wet conditions.
Just moments after Nico Rosberg's Mercedes went wide at Turn 1 due to the damp track, the Dane also went sliding off in the same area. However, while Rosberg managed to get his car back on track, Magnussen went side-on into the tire barriers causing quite a lot of damage to his chassis.
McLaren have been forced to change his chassis and gearbox, which will result in a start from the pitlane.
"I just hit the wall. The track was much wetter at the first corner than it was at the last corner," the Dane said.
"As I came out of the final turn, there was full grip, so I braked for Turn One at the normal braking point, but it was much wetter. Physically, I'm fine but I'm sad that I didn't get more out of it. I'm most disappointed for the team, I think we could've got another decent qualifying result.
"Now, we just need to get on with it – starting from the pitlane will make life more difficult, but I'm determined to have a strong race. I'm just very disappointed to have made that mistake."
Lewis Hamilton will start the Hungarian GP from the pitlane after his Mercedes car suffered catastrophic damage when it was engulfed in flames at the start of qualifying.
In another blow to his faltering title prospects, Hamilton's Mercedes team have announced that, in addition to a change of gearbox and engine, Hamilton will use a new chassis for Sunday's race – triggering a pitlane start alongside McLaren's Kevin Magnussen.
Hamilton's W05 caught fire in the opening minutes of qualifying as the Englishman failed to make it through Q1 for the second time in a week due to a mechanical failure. Mercedes have identified a fuel leak as triggering the fire but are yet to determine the cause of the leak.
"We are still stripping the car to understand the cause of the fuel leak but the symptom was a loss of high pressure fuel to the direct injection system of the internal combustion engine," confirmed technical chief Paddy Lowe. "This fuel leak then caused a major conflagration which is likely to have written off most of the car."
Following Magnussen’s crash into the barriers during a brief rain shower in Q3, McLaren have confirmed that the young Dane will start the race from the pitlane after the accident necessitated a change of gearbox and chassis.
And with the rear of his Mercedes shredded by the flames that burst out of the W05, similar changes – and an identical starting berth – have also befallen Hamilton.
Article 28.2 of the Sporting Regulations states: 'Any driver who decides to use another car or whose car has a change of survival cell following the qualifying practice session must start the race from the pitlane – a switch to the team's spare means a pitlane start.'
Although Hamilton charged through the field at Hockenheim on Sunday to finish on the podium after starting out on the back-row, the prospects of a repeat performance are remote this weekend given the restrictive nature of the tight and twisty Hungaroring.
"This is a track that you cannot overtake on so I think I will struggle to get in the top ten tomorrow or at least the top five," Hamilton told Sky F1.