help, getting to the monorail then to delta labs

Ok Im in the communications place where you send a message to earth asking for reinforcements. Where exactly do you go, to goto the monorails which gets you to the delta labs???

After you send/cancel the message, you need to head down into the maintenance level. Going through there will take you back to the garage and then you can go back through to the Comms lobby, where the door to the monorail will be open.