Train Quito - Guayaquil

Hello all,
I am usually not a member of your forum in Quito, but I have a urgent question. So even if I met some of you already on other places in internations in order to get a quick answer I decided to write a question into the forum.
Here it goes: my then just barely 16-year-old son will travel to Ecuador this coming summer with a government sponsored school exchange program. He and three other students and a teacher will be staying somewhere in the province of Manabi with host families for a few weeks. Today now the teacher proposed taking the Protected content on a trip to Quito during that time. She wants to fly from Guayaquil to Quito, do Protected content of touristy things there and then tale a train from Quito back to Guayaquil. My question: is it safe to take that train?
The teacher speaks Spanish fluently, the 4 American teenagers don't. Most of all, except for my son, they all are blond and blue-eyed. The teacher will be recognized as a typical American from 2 km distance. Will they be safe on this train trip?
Sorry, this is so urgent, but we must make a decision until tomorrow morning, so any quick input will be highly appreciated. Thanks! Ulrike