Memory Alpha suggests that each starship contains redundant transporter systems. It'd make sense that a high traffic machine that can literally kill you if the operator sneezes would have some sort of automated safety/backup systems.
The glitch in TMP is never fully explained; the usual "rule of plot" should suffice to explain it.
In-universe, it's apparently a freak accident with a number of highly unusual circumstances coinciding to produce the tragic outcome; it seems that the E was working and all of a sudden experienced a catastrophic glitch during re-materialization; meaning only a single transporter unit was running and failed too quickly for the computer to transfer it to different transporter room or send the signal back to SFHQ.
The glitch in TMP is never fully explained; the usual "rule of plot" should suffice to explain it.
In-universe, it's apparently a freak accident with a number of highly unusual circumstances coinciding to produce the tragic outcome; it seems that the E was working and all of a sudden experienced a catastrophic glitch during re-materialization; meaning only a single transporter unit was running and failed too quickly for the computer to transfer it to different transporter room or send the signal back to SFHQ.
Stargate SG-1 had that in an episode; a small cargo shuttle drops a few "remote" transporter pads so the soldiers could transport in en-masse* (*Stargate does not have site-to-site transporting until the last two or three seasons. A receiving pad is always necessary)If having a transporter pad to beam to is such a big issue on a planet where none would be, here's a bright idea: beam down a transporter unit set to activate upon re-materialization first and send the people and goods that you're trying to transport to it.