Mysterious new sign appears on metro screen doors

This photo was taken at the Changshu Lu subway station yesterday. See that new yellow sign? It says:

When the alarm starts sounding and the platform screen door lights start to blink, please do not board or alight the train.

We wonder if that sign has come up because of last month's death of the unlucky man who got caught between the subway and platform screen doors. Micah Sittig has a translation of a chilling eye-witness account of the man's death, found on Ditiezu.com:

I happened to be on the scene of the incident that happened this afternoon.

At the time I had just gotten off the train and walked over to the escalator. As the warning beep was sounding for the doors to close on the train from which I had just disembarked, I saw the victim following the people in front of him onto the train. But when the safety doors closed at the same time as the train doors, the guy got stuck in between and could neither enter the train nor get back onto the platform. At that time the guy and the people in the area all started yelling, so a platform staff member came over and started wildly blowing his whistle, trying to tell the driver to not start the car and getting ready to open the safety door. But the driver didn't react to the whistling and started to pull the train out of the station.

I was too scared to look. Since I was already halfway up the escalator I didn't personally see the man die, but I could hear the onlookers screaming and a bumping noise. Later on, after the train had left, I thought about going back down but since I was scared I thought better of it and left the station to meet a friend.

Actually, it wasn't like you might imagine: the guy didn't try to jump onto the train until the warning beep had already started, and he was really just following the crowd onto the train. It's just that since it was pretty crowded so he didn't have time to push his way into the car, and that's why he got stuck. I think that the responsibility for this accident actually lies with the Metro Company, because even after the platform staff had discovered the man and started whistling the driver of the train didn't understand what what going on. I mean, even under normal conditions the staff will whistle to signal that everything is clear and the train can leave. So I think that that the company is responsible for not creating a standard signal between the platform staff and the drivers, and that if there was a standard signal that the staff could make that the driver would understand and not start the train, then in today's situation the accident would have been avoided. So I think what's missing is a signal between staff and drivers for use in emergency situations, that is to say a signal that would emphasize that it's NOT ok to start the train.

As for the passengers, the ones standing on the platform at the time, what we could have done is to communicate the situation to the driver, by yelling or screaming; the passengers inside of the car could pull the emergency handbrake (I don't know if this is OK, whether it would be illegal in this case), or pull/hold the doors of the train open and not let them close. It seems like it's impossible to hold the safety doors open, but if you stick something in between the train doors they will automatically open when they meet the obstructing object.

Those have been my thoughts on the matter. Lastly, I grieve for the life that was lost today, and hope that such a tragedy will not be repeated. It is our wish that blood and death will not grace our beloved metro system. So, everybody, please be careful the next time you take to the rail!

Related link
Shanghaiist: How safe are our metro platform doors?
Ditiezu.com: Today I saw the guy trapped and killed in the safety doors on Line 1, and I'd like to say a few words