According to the article, only three people in a car near the suspected truck died from the explosion. Maybe it is just poor writing, but this implies that the truck driver survived, which is hard to believe.
That is hard to believe. It was a massive explosion.
Most don’t die from fire or shrapnel, but the pressure wave.
In many videos you can see the car explode in flames when the fireball hits it - the people were likely incinerated instantly.