Voice of Reason is suspected to have lost its life to something not-so-reasonable.

A young Mounted Police horse, named Voice of Reason, which was on duty outside the Eden Gardens on Sunday died late in the night after colliding with vehicles, hours after several on-duty horses started running helter-skelter hearing the sound of firecrackers burst outside the stadium after India’s thumping win over South Africa.

Officials at Mounted Police said the mare died of “internal injury and traumatic shock”.

Voice of Reason had galloped away along Plassey Road after hearing the sudden burst of crackers.

“It was a racehorse that was inducted into Calcutta police earlier this year. On Sunday, it went galloping along Plassey Road at full speed hearing the crackers and then it hit two or three vehicles and crashed on the road,” said an officer who was present on the spot.

By the time the police came to its rescue, in the middle of the road, it was lying immobile.

An officer said the saddle had to be cut open to revive the mare and take it back to the stable, less than a kilometre away. Five minutes after reporting back at the stable, Voice of Reason collapsed, the officer said. Several other horses were similarly injured.

Cricket Association of Bengal secretary Naresh Ojha told this newspaper that the fireworks that were used were ones that were also used during the IPL. "We had prior permission from the Pollution Control Board and Calcutta police," he said.

According to veterinary surgeon Swapan Kumar Ghosh, horses, like all other animals, have a very sharp sense of hearing. “The impact of the same sound is much higher for animals than humans as their ears are extremely sensitive,” Ghosh said.

Ghosh said Mounted Police horses were not completely unfamiliar with noise as they regularly do Maidan duty and are called in to tackle law-and-order situations.

The vet, who has served with the Alipore zoo, the Calcutta police dog squad and the Mounted Police, said: “It is difficult to say exactly what happened; Mounted police horses have been engaged in Eden Gardens duty for several years now.”

A Calcutta police officer said 21 horses were selected for the “high voltage” match on Sunday considering their age and agility.

“Voice of Reason was a relatively young horse and was in the best of health. Because it was going to be on long duty hours from 11am till the end of the match, we chose the young and healthy. Voice of Reason worked without a break," he said.

"A few were brought back to the stable in between for rest but a skeletal force was on duty through the match," said an officer.

After the crash, as Voice of Reason trudged back to the stable, inside the compound of the office of the deputy commissioner of police (central division) on SN Banerjee Road, an officer who saw it for the last time said: "The team returned around 10.15pm. Within a few minutes, this horse started to nod its head from one side to the other and then slowly downed its head. A few seconds later, it collapsed on the ground."

The mare underwent post-mortem early on Monday and was cremated at Dhapa. "It had no external injuries except a small cut near one of its eyes. It died of traumatic shock," said an officer of Calcutta police.

At least three other horses were injured, some of which had to be put on saline or given intravenous injections.