A major flooding incident occurred on the 11th floor of the apartment tower at 100 Van Ness, and it's allegedly the work of a vandal who lived in the building, and who was found at the scene.

Multiple social media reports went out early Tuesday about a fire alarm and flooding incident at 100 Van Ness, which is home to hundreds of residents who were awoken to the alarm around 5:30 a.m.

Images showed several inches of water in hallways, possibly on multiple floors, and flowing down stairwells like a waterfall.

Somebody had a really good/bad time Monday night into Tuesday morning, and it ended with a hole apparently being busted in a wall in one of the building's stairwells, and a font of gushing water, perhaps from a fire line or other large water pipe, that had been broken open or otherwise unleashed.

The SF Standard reports that firefighters responded just after 6 a.m. and found a 46-year-old resident of the building "drenched in water" and located near the source of the flooding. That resident has been arrested on suspicion of felony vandalism.

Residents told the site that they saw a large hole in a wall in the western stairwell, around the 11th floor where the incident took place.

Because of the recent flooding incident(s) at 33 Tehama, residents immediately thought something like that had happened, before it became known that a vandal was at fault.

So far the suspect has not been publicly identified.

the 29-story 100 Van Ness, formerly an office tower for the California State Automobile Association, was converted into 418 rental units that opened for leasing in 2015.

Elevators in the building were disabled due to the flooding, and the extent of the damage is not yet known.

Update: The resident in question, who was arrested, has been identified as Michael Nien — and, naturally, he was naked when firefighters found him near the fire hose valve he allegedly opened, unleashing a torrent of high-pressure water.

As KTVU notes, Nien's open Facebook account includes a series of screenshots of text conversations in which a person, who seems to be a neighbor in the building, was threatening physical violence against him. Nien also posted on October 1, "I cannot express the number of emotions I have for the management of 100 Van Ness Ave (a couple of prior complaints towards the same neighbor months prior towards management before) and SFPD after I called them starting at 1:30 AM when my neighbor below 1 floor threatened to stab and kill me with a slew of texts and voice mails and facetime requests."

In a very early morning post that same day, Nien wrote, "Well. If anything happens to me. Thanks 100 Van Ness and SFPD."

Another resident of the building described to KTVU how a neighbor "physically stopped [Nien] from attacking the pipe," and added that Nien "was having some kind of mental episode maybe."

Top image: Photo by Wagnerian/Twitter