Water has been cascading through downtown Toronto all morning, turning subway stairs into waterfalls and causing many an unexpected soaker.

And for once, it's not the weather's fault.

Another reason to wear rain boots today. Broken water main on Yonge St. between King and Wellington. @TorontoStar pic.twitter.com/8Zr91UTPs9

— Braydon Holmyard (@BraydonHolmyard) May 3, 2018

Toronto Police say that water started bubbling up onto Yonge Street near Wellington around 3 a.m. this morning.

By 5 a.m., crews had determined the problem: A water main from the late 1800's burst just south of King Street.

Yonge/Wellington flooding update:crews tell me the turning nut on top of this old water main dating back to 1800’s has broken off so they can’t shut off the flow of water. Workers are enroute with more equipment to try and do the job. pic.twitter.com/G3rYKLqkb8

— carl hanstke (@carl680) May 3, 2018

Officials initially closed off Yonge Street in both directions near the bubbling grates due to a "large amount of water pouring down street," though only the southbound lane of Yonge between King and Wellington streets remains closed heading into the morning rush hour.

Transit-wise, the 97 Yonge Street bus is diverting southbound via Adelaide, Church and Wellington streets.

A river running down Yonge St south of King reminds us of the value of our underground water infrastructure that we rely on every day! #OntarioWater sector has great solutions for infrastructure inspection and rehab @WaterTAPOntario supports our water sector! #6ix #water pic.twitter.com/ocSeOwX7OQ

— Peter Gallant (@PeterGallantWT) May 3, 2018

Subway service has not been impacted, according to the TTC, but both the Commerce Court entrance and Melinda Street exit at King subway station remain closed.

Crews are making progress in figuring out how to get the water under control, but it's still a pretty messy situation. Avoid the area, if you can, or at the very least wear some proper rain boots.