Flatbush Gardener has an incredibly interesting post about the Malbone Street wreck, the worst transit disaster in NYC history, which occurred just outside Prospect Park. Here’s an excerpt from FG.

On November 1, 1918, the worst transit disaster in New York City history
occurred just outside Prospect Park and the Brooklyn Botanic Garden.
The wooden cars of the Brighton Beach line of the Brooklyn Rapid
Transit (B.R.T.) company left the tracks, crashing inside the tunnel
beneath the busy intersection where Flatbush Avenue, Ocean Avenue and
Malbone Street met [Google map].
The Malbone Street Wreck killed nearly 100 people and injured more than
250. Criminal trials and lawsuits arising from the accident dragged on
for years.