Firefighters in San Francisco had their hands full Sunday fighting two large fires.

The biggest was a four-alarm fire at 1526 Wallace Ave. in the city's Bayview District. That fire reportedly burned several warehouses.

The fire was first reported around 11 a.m., but crews were still dousing the flames at 5 p.m.

The structures included a cabinet and metal manufacturer and one source told NBC Bay Area that one of the buildings contained a marijuana growing operation.

Investigators say the fire did not start where the pot was growing. It is also not clear if the marijuana was legal medical pot or an illegal drug growing operation.

Crews faced a number of challenges, including the wind which hampered the fight.

Spotted here