KANSAS CITY, Mo.  Sometimes avalanches start through natural causes. Other times there is a trigger that sets them off.

Bill O’Brien triggered an avalanche on Sunday.

The Texans coach watched his team take a 24-0 lead at Arrowhead Stadium in the AFC Divisional Playoffs against a Chiefs team that could not get out of its own way early with special teams gaffes and dropped passes. It felt like Houston would be the second AFC South team in two days to pull off a playoff shocker.

Then, O’Brien made one of the worst coaching decisions you’ll ever see.

After playing it conservatively on the previous drive with a fourth-and-1 field-goal attempt, O’Brien turned into a riverboat gambler a few miles away from the Missouri River. O’Brien called a fake punt on fourth-and-4 from his own 31-yard line. The direct snap went to Justin Reid who gained 2 yards before being tackled by Chiefs safety Daniel Sorensen.

At the time of the fake punt with 8:32 remaining in the first half, the Texans were leading 24-7. Two minutes later, the lead was 24-21. By halftime, the lead would be a memory.

Patrick Mahomes and the Chiefs scored touchdowns on seven straight possessions, a first in NFL playoff history. They scored 41 straight points on the Texans in all, outscoring the Texans 44-7 after the fake punt.

Kansas City won 51-31 and advanced to the AFC Championship game for the second straight year. They will play the Titans next Sunday at Arrowhead Stadium.

They should send O’Brien a fruit basket to thank him. He performed CPR on the fading Chiefs with his perplexing decisions on two kicks in the second quarter.

After the game, O’Brien tried to explain the fake punt.

“We felt like we weren’t going to be able to punt it too many times today,” O’Brien said. “We felt like we had to try to manufacture some points, manufacture some yards. It just didn’t work out. It was something we decided to do, but the play didn’t work.”

O’Brien said he felt like no lead was safe against the Chiefs. That Mahomes was so explosive the Texans would need to score 50 to keep up. That is why he rolled the dice on the fake punt call.

OK, but then why settle for a field goal on fourth-and-1 at the Chiefs’ 13-yard line? Why not keep your foot on the gas and try to score seven points and not settle for three? Carlos Hyde was running well. Deshaun Watson could have plunged forward for the first down. If you fail, the Chiefs are down three touchdowns with 87 yards to go.

O’Brien seemed hung up on the third-down play before it when Duke Johnson looked like he might have the first down, but the ball was spotted short of the marker. O’Brien considered challenging the call, decided not to, then called timeout anyway as the play clock ran down.

“I felt like I had a first down there and when I didn’t I felt like we didn’t have a great play there for the fourth down at that point in time,” O’Brien said. “I felt like it was better to kick the three. That’s a very fair question, but I felt like it was just better to kick the field goal there.”

Chiefs returner Mecole Hardman took the ensuing kickoff 58 yards to the Texans’ 42. Two plays later, Mahomes hit Damien Williams for the Chiefs first of seven touchdowns in the game.

The avalanche was on.

O’Brien’s players did not help him. He was not the one who could not cover Travis Kelce (10 catches, 134 yards, three touchdowns). He did not fumble a kickoff that gave the Chiefs the ball at the Houston 6. He did not commit pass interference to give the Chiefs great field position. He did not fail to get pressure on Mahomes.

But he triggered the avalanche. It was an inexcusable decision that sent the Texans home and gave the Chiefs a date with the Titans.

“I think these games are always games of momentum, momentum swings,” O’Brien said. “We had momentum at that point. It just felt like we were going to try to make a play there and it just didn’t work.”

Coaches consistently get too much credit and too much blame in the NFL. But this one was on O’Brien. The Texans sideline looked like a deflated balloon after the failed fake punt.

O’Brien triggered the avalanche and it swallowed up his team.

Ref;nypost.com