MEXICO CITY — Word spread quickly: free gasoline. It was spewing from a pipeline, through a hole punched by fuel thieves. People — as many as 900, by some estimates — flocked to the rupture, many carrying containers to fill.

But just as quickly, the apparent windfall on Friday turned to disaster when the pipeline exploded in flames, killing at least 89 and wounding scores more.

Amid the national lamenting, some Mexicans have insisted that the victims had only themselves to blame: They were breaking the law, pilferers taking what wasn’t theirs, and had put themselves in harm’s way.

But the man steering the nation’s response to the incident, President Andrés Manuel López Obrador, has rejected that view, arguing that the people were compelled to participate by the poverty and unemployment caused by past government policies.