Helped a friend deal with a broken water pipe between the main line and his house. OUCH!
Had the same problem recently. Water line between the meter and the house (our responsibility) developed a leak. First we knew of it was when the water department sent us a letter saying that they noticed a large usage and we should check for leaks. Our meter is only read four times a year.
First plumber said they could do nothing until the location was identified. It's about ten feet from the meter to the house. We got a leak detection company to look at it and they identified the location, four feet from the house and five feet down.
The plumber then came back and started digging with a shovel (the location is nothing but gravel and clay). After an hour or so they gave up and said they would be back some day. I told them not to bother.
Called a different plumber and they did the right thing by getting all utility lines marked. Brought in an excavator and dug to find the leak. Turned out it was about five feet away from where the leak detector said it was, and six feet below ground level. They fixed it and it seems to be good.
End of the story: a bit over $4K plus the cost of the extra water that leaked.
Things like this are a great example of what we call "unplanned expenses" that are nevertheless completely necessary.