verb/aɡaˌraɾ ˌfweɡo el kaˈɲal/
to have a situation or problem get more complicated or worse; to have a situation or problem go downhill.
“Cuando él la insultó agarró fuego el cañal.” — When he insulted her the situation got worse.
Literally, “(to have) the reed field catch fire”, from the traditional practice of burning reed fields before harvest.