Drain clogs

Homeowners can often fix drain clogs themselves if the problem is confined to specific fixtures such as a sink drain or a toilet. However, when all drains are affected — or when you see warning signs, such as water going down one drain and backing up in another — that generally means the main drain is clogged. Call a plumber who specializes in clearing drains.

If it’s a blockage from something flushed down a toilet, clear the drain by using a plumber’s auger or snake. However, in older neighborhoods, the cause may be tree roots. Older sewer lines were made from fired clay and as they age and weaken the tree roots creep in.

Drain experts are often able to bore through the roots and clear the drain, but in many cases the original drain pipe has become so deteriorated that the new passageway eventually collapses. When this happens the drain line usually needs to be replaced.

When lines become clogged and damages occur, in the majority of cases, the homeowners’ responsibility begins at the connection point to the city sewer system and includes the lateral lines and all drain plumbing in the home. Any maintenance, repairs and unclogging of these lines must be done by the homeowner, often with the help of a plumbing service.

While the indoor piping is relatively easy to repair, underground lateral lines require specialized equipment and tools, so those repairs often require a plumber.

As the others have said, your drain line is blocked someplace downstream of both the tub and and sink causing the water to come back up and out the sink's drain. A plumber should be able to take care of this fairly easily.

Regarding your cabinets and floor - if they are damaged then this is likely covered under your homeowner's insurance. You insurance company can also put you in touch with a local company that can do water damage mitigation which should be done right away to help limit the damage. The mitigation services should also likely be covered by your insurance. I would call your company/agent right away.

Sounds like your plumbing is partly clogged. You should have your drains cleanout pipes professionally cleaned at least once every two years.

your drain [sewer line] is plugged, or partly plugged. it needs to be snaked out. call handyman and explain task

You got clogged drains

Call a plumber to find out what is wrong. Likely a clogged waste pipe. Liquids always find the next cavity to flow out of.