@@I_also_like_sirens_heheI meant the siren itself, though it would probably be from the super powerful blowers these had. The buzz is hard to hear given the muddy vhs quality, but listen closely at about 0:06, it can be heard at fleeting moments when the siren faces right, very interesting. If you want to hear it very clearly you can listen to the garland recording, it’s VERY prominent and striking.
Plus, the Hurricane was made when the concern for civil defense was at a decline, were as the FS Thunderbolt and H.O.R. Sirex series had been around since the start the Civil Defense Act.
I think that this Hurricane was replaced with the P-10 at Lincoln Park, because that P-10 is located only a couple blocks away from the North Shore Montessori School, and the P-50 was located about 2 miles away from there.