BART gives clear, loud warnings.
Husband tethers one of our dogs to his waist when we walk and I've never liked it.
I saw a video where a woman pushed her baby stroller into the train car, then stepped outside to answer a sudden cellphone call. Doors close. Woman runs around shrieking. Maybe that's what happened here.
Happy ending. It turns out there was a drunk on board the car, sees what happened, gets off with the kid at the next station and waits for momma. Next train comes along and momma spots the kid. Runs out screaming with happiness and hugs the drunk. While she's doing that, drunk takes another swig from his bottle.
I used to take my dog for walks with my bicycle. She loved it. Then she became a runner. As soon as I was on the bike she’d take off running as fast as she could for about half a block pulling me. But! She got to where if she saw another dog or cat or anything else she’d try to go after it. Scared me since she’s 75 lbs....so we stopped the bike runs. I was using a bicycle dog leash. They’re attached to the bike.