The company I work for were the genaral contractor of a job and we had a sub contractor putting up a retaining wall for us and they hit a buried powerline and it was flopping around like a fish. Very dangerous but luckly nobody got hurt. The sub tried using our (generals) locator service number and that was illegal because they didn't call in there own locator service, they where nailed with a $4000 bill. Even with multiple contractors digging on one job, each must call in.