All of a sudden engine locked up

Any helps appreciated. Thank you.

Please help!

No leaks. No overheating. Since car cut off in highway. Could not tow to oil change place towed to nearest place in which they checked dipstick had oil. I put in a new battery did not need. Got new starter did not need. Then another guy looks deeper says oh no, no oil. And something in lower level not connected. Mind you guys at advance auto looked at this. Called oil change place told them what I was told. They get smart say have mechanic call me. And hangs up. My cars in Maryland I am now in Pennsylvania. Mechanic said looks like when the oil change was done they did not connect oil plug. Then tells me I need an engine. I am devastated.

There was no oil leakage in my parking spot. I only drive ti work and home. Car stays parked mainly. Until I drove to Maryland. In which I checked the oil stick before I jumped on the highway and it had oil on it. Could it had leaked while I was driving no more than two hours away? Is there any way to unlock engine now that its been sitting a week?

I want to faint!

When the oil change was done it wouldn't an oil leak be noticeable? But again no oil in my parking spot at work or home.

Thanks, I have been told that. Having a mechanic look at it thoroughly to be sure the problem, but I think the drain plug is the issue.

Will definitely keep you posted, thanks so much.